Exploring Private Investigation Agencies’ Experience of Collaboration with Law Enforcement in Investigations of Human Trafficking Cases

Abstract

In their forefront role to address human trafficking, law enforcement agencies (LEAs) have often faced challenges in efforts to investigate this crime. Non-traditional partnerships should be explored to improve strategies to investigate human trafficking. Could private investigation agencies (PIAs) collaborate with LEAs to help improve human trafficking investigations? The present study examines PIAs’ experiences of collaboration with LEAs for human trafficking investigations. A mixed research method design was used. Purposive sampling was used to select 81 participants representing 81 PIAs for a survey. Follow-up semi-structured interviews were conducted with 28 of the 39 survey participants who reported that their agencies had collaborated with LEAs for human trafficking investigations. The findings show varying levels of success and challenges for PIAs in interagency collaboration with LEAs. The challenges to collaboration identified could be mostly explained by LEAs’ misperceptions of private investigators, their over-reliance on a criminal approach instead of a victim-centered one in investigating trafficking cases and recovering victims, and legal or ethical limitations. Positive aspects of PIA–LEA partnerships regarding human trafficking investigations were discussed and so were strategies to address inherent challenges to interagency collaboration. Several policy implications were discussed for developing and improving partnership initiatives with law enforcement in an effort to prevent human trafficking, protect victims, and prosecute trafficking cases.

1. Introduction

Law enforcement agencies (LEAs) play a frontline role in efforts to prevent human trafficking, protect victims, and investigate trafficking cases [1,2,3,4,5]. Yet, their efforts to investigate human trafficking cases and recover victims have often faced challenges due to varied reasons, including misconceptions about the problem, community fear and distrust of law enforcement, an insufficient number of officers, a lack of training about the problem and its scope, limited appropriate resources, reliance on reactive identification strategies, and limited interagency collaboration [1,2,6,7,8,9,10]. Most state and local LEAs in the United States lacked specialized units or personnel dedicated to human trafficking [1,10]. Having many crime investigations to conduct, police departments are rarely proactive on crimes such as human trafficking or such investigations are often closed prematurely [11,12].

Human trafficking investigators are primarily found in the sex crime or vice units of police departments, and they focus primarily on sex trafficking [1]. LEAs have difficulty identifying and investigating labor trafficking because the use of traditional vice tactics, such as responding to referrals about potential victims or relying on non-governmental agencies or other law enforcement agencies to provide tips in investigating sex trafficking cases, are ineffective in dealing with labor trafficking cases [8,10]. Discussing LEAs’ difficulty in dealing with human trafficking crimes, Nietzel, a 15-year police veteran and human trafficking investigation specialist, observed that law enforcement officers often found themselves looking at so many different avenues and so many other labor markets that they were not able to be proactive in human trafficking investigations [13].

LEAs acknowledged that collaborating with specialized organizations other than LEAs that deal with this problem is crucial [13,14]. The International Association of Chiefs of Police (IACP) [15] found that partnering with outside organizations and individuals allows LEAs to effectively investigate trafficking cases, identify and recover trafficking victims, and support the prosecution of traffickers through joint responses and coordinated services. Thus, increasingly LEAs rely on collaboration with partners in the private and nonprofit sectors to reinforce their capacity to investigate human trafficking cases [7,14,16]. Nietzel [13] stated that “Collaboration among law enforcement is vital for human trafficking investigations, but equally as important are the partnerships formed with victim service providers and other community stakeholders” (para 4).

Developing innovative partnerships is necessary to improve LEAs’ capacity to investigate human trafficking cases and recover and protect victims because, as Nietzel observed, “Human trafficking can absorb a lot of an investigator’s time. The solution is having partners who are trained to do this. It’s important for agencies to realize that help is available and they don’t have to do it alone,” (para 2). A question raised by Nietzel’s point would be to know what types of trained partners, outside of LEAs, can potentially enhance human trafficking investigations. Could professionals in the private police sector, especially private investigation agencies (PIAs), supplement and assist LEAs in improving human trafficking investigation outcomes?

While there is some literature about collaboration initiatives between law enforcement (i.e., public police) and private police in areas of security such as terrorism and cybersecurity during the last five decades [17,18,19,20], there is almost no literature, however, about partnerships between the two sectors regarding human trafficking investigations. The present study explores PIAs’ experiences and perceptions of collaboration with LEAs on human trafficking investigations through three research questions: (1) How do PIAs perceive collaboration with law enforcement on human trafficking cases? (2) To what extent have PIAs collaborated with LEAs on human trafficking cases? (3) What potential benefits and challenges can be drawn from PIA–LEA’s interagency collaboration for human trafficking investigations?

1.1. Law Enforcement–Private Police Partnership Crimes

Private police, also known as private security, are law enforcement bodies that are owned and/or controlled by non-governmental entities [21]. They provide a broad range of services to prevent crimes and protect persons and property from injury, hazards, damage, loss, and criminal acts [21,22,23]. These can be firms to which the government may contract out police work. Private police remain largely overlooked in the literature because researchers, especially those who study the police, have paid very limited attention to private policing [18,24,25]. Yet, the functions of private police and public police (i.e., law enforcement) are increasingly similar [17,18,26]. Both private police and law enforcement are concerned with crime prevention and reduction and order maintenance [22,27]. The primary role of private police, that is, crime prevention [28], is often misunderstood and misinterpreted by law enforcement personnel, which makes it difficult for the latter to embrace “private security efforts as complementing and assisting public efforts in crime prevention and reduction,” [22] p. 7. The overwhelming presence of former law enforcement officers in the private security sector suggests a considerable overlap between the activities of the private police and the public police [24].

Research shows that the private police industry is by far the largest provider of policing services in the United States, with at least triple the size of the public police [18,20,29,30,31,32,33]. Policing services include protecting citizens and property, surveillance, maintenance of order, crowd control, crime prevention, conducting investigations, providing information technology security, and many other functions [20]. They have outpaced the public police in terms of persons employed and dollars spent [16,20]. According to the U.S. Department of Labor Bureau of Labor Statistics [34], by May 2020, there were 1,054,400 private security officers in the U.S. In contrast, there were 696,644 full-time law enforcement officers employed in the U.S. [35].

Even though the need for more cooperation between private police and public police has been documented, issues of mutual distrust affect their relationship [20,36]. The main obstacles to collaboration between the two sides of policing include limited information sharing, mistrust, misinformation, and competition [16,24,37,38,39]. Historically, law enforcement officers have often shown a patronizing, suspicious, and antagonistic attitude toward private security professionals [20,22,27,38]. Their unfamiliarity and limited appreciation of the private security sector’s policing roles contribute to this distrust [22,36,38]. Police officers perceive that private police agents lack appropriate training and are threats to the professional policing domain [16,24,27]. Despite the lingering distrust between the public police and private police sectors, some efforts for partnerships between both sides have been made [23,40,41].

In its (2009) Operation Partnership report, the Law Enforcement–Private Security Consortium [20] of the U.S. Department of Justice Office of Community Oriented Policing Services reported that, as of 2006, over 450 private security–public police partnerships were established in the United States. The success of these partnerships focuses on several major factors, including a compelling mission to keep members interested and attract new members; external support of models for training; strong, active founders, leaders, and facilitators; regular communication through meetings, training, newsletters, websites, etc.; and established methods to sustain structure and sufficient resources [20]. In some U.S. cities, private police agencies have been given law enforcement powers to provide certain police functions (e.g., protecting public property, surveillance, crowd control, crime prevention, conducting investigations, providing information technology security, etc.) so as to decrease resource costs and improve policing services in a particular area [33]. For instance, Ruddell, Thomas, and Patten [42] examined the deployment of public police and private police officers in the 300 most densely populated U.S. counties. They found a clear and consistent relationship between crime and the deployment of officers from both the public police and the private police. Their study showed that private police personnel have a significant role in expanding the activities of the public police by shaping urban social control. The percentage of the county population that was Black and the underclass factor were positively associated with the deployment of private police officers. It was also found that private police forces were more likely to be deployed in high-crime counties than their public law enforcement counterparts. However, while LEAs have established formal relationships with big, private police agencies, such levels of cooperation rarely extend to PIAs, a key component of the private security sector [18,25,42,43,44].

1.2. What Is a Private Investigator?

A private investigator (PI) is licensed to carry out various policing services, including finding missing persons, carrying out surveillance, preventing crime, and collecting factual evidence that could help solve crimes [36,44]. Allan Pinkerton, a former deputy sheriff of Cook County and the chief of police of Chicago, Illinois, established the first professional private investigation organization, the Pinkerton Detective Agency, in the United States in 1850 [28]. Pinkerton formed his private investigation agency because LEAs at that time were unable to cope with the increasing crime problem in the United States. Thus, during that time, he offered nationwide investigative coverage by his detectives, something that no LEA was able to offer. As Benny [28] stated, “It was not until 1924, with the establishment of the Federal Bureau of Investigation (FBI), that any law enforcement could equal Pinkerton’s scope and size of operation,” (p. 3). During the Civil War, Pinkerton provided a valuable service to the United States by organizing the first Secret Service to stop the counterfeiting of U.S. currency by the Confederates and collecting intelligence on behalf of the U.S. government. In essence, Pinkerton was providing homeland security for the United States. Because of his reputation, Pinkerton and his PIA were hired to protect Abraham Lincoln personally during his inauguration. Before that, he suppressed an assassination attempt against Lincoln [44]. Many law enforcement agencies in the United States began as PIAs. For instance, the U.S. Secret Service was formed out of necessity after the assassination of Abraham Lincoln and was initially protected by the private Pinkerton Detective Agency.

PIs do not have the special power that law enforcement officers have [44]. Yet, they have a legal right to make a citizen’s arrest under restrictive circumstances. They may carry firearms based on the legal requirements of the country or state in which they operate [28]. Laws governing the licensing and practice of PIs vary from state to state in the USA. Some U.S. states have reciprocal licensing agreements allowing a licensed PI to start an investigation in one state and continue it in another [28]. Regardless of the area or industry in which they work, PIs follow a strict set of standards dictated by state law. Many PIs are members of state, national, and international professional investigator associations, which also require them to work under a code of ethics [28,43,45].

Many PIs hold college degrees along with various types of professional certifications. A great number of PIs are former police officers, former government secret or undercover agents, former investigators from other fields (e.g., federal law enforcement, insurance, law) [44]. Most PIs are self-employed, and some work as investigation specialists in large private security corporations [44]. They perform different types of investigations, including, but not limited to, domestic investigations, employment investigations, undercover investigations, fraud investigations, claims investigations, corporate investigations, background checks, and criminal investigations. In criminal investigations, PIs work either for the victim or the defendant, or attorneys in the proceedings of serious crimes such as homicide, car accidents, fraud, and kidnapping [28,44,45]. In 2019, there were approximately 96,100 licensed PIs in the U.S. [34,46].

1.3. PIs’ Distinctive Competencies

The literature shows that PIs not only have various investigative competencies, but they also operate in both the private and public sectors in different capacities. In a qualitative study with 33 PIs specialized in corporate investigations in Australia, King [47] found that corporate investigators not only share detective skills with the police but also rely on knowledge of law and accountancy to complement these investigative skills. In a survey of 206 PIs working in the UK, Gill and Hart [24] found that they had provided various policing services in the previous 12 months before the study, including road traffic accident inquiries (81%); claims investigations (72%); domestic investigations (68%); criminal investigations (53%); fraud investigations (50%); and asset tracing (51%). In another survey of 331 PIs in the UK, Button, Kapend, and Stiernstedt [36] found that the most significant skill of participants was fraud investigations. It was estimated that approximately 15,000 PIs are employed in the UK’s central government for fraud investigations and intelligence work [36]. Most forms of surveillance in the UK are the responsibility of PIs.

In the United States, PIs are hired to conduct investigations for governmental agencies at various levels, thus directly contributing to national security. According to Benny [28], “Numerous federal agencies, such as the Defense Security Service, the Office of Personnel Management, and even the Federal Bureau of Investigation contract private investigators to perform routine background investigations related to government security clearances” (p. 25). Likewise, throughout the nation, state and local government agencies hire PIs for various investigative functions such as pre-employment background checks, security consulting, or assignments with a special prosecutor investigating government corruption, ethics, or agency regulation and policy violations [28]. Still, in the United States, many local courts contract PIs for pretrial investigations for a public defender’s office; civil service commissions also employ PIs for background investigations on potential police officers or other public employees. Overall, the future employment outlook of the PI profession in conducting traditional investigations as well as national security investigations in the United States is projected to grow by five percent from 2015 to 2024 [28].

In some areas of investigations, PIs arguably outpace the ability of police officers [23,28,40,44,48,49]. PIs can draw from their various skill sets to conduct investigations that law enforcement cannot carry out due to legal or administrative hurdles (e.g., the volume of their investigation workload, standard operation procedures, delays in obtaining a judge’s warrant for a search, etc.) [48,49]. Some PIs are able to provide crime prevention services not usually available from even the best police departments [28,40,44]. Time is not a big obstacle for PIs because, contrary to police officers, they tend to focus on single investigations until completion [49]. They have advanced interview and covert/overt surveillance competencies and are not burdened by the need to handle as many investigation cases as police officers [48]. The past professional law enforcement experience of most PIs could be considered another major asset for the profession. PIs can provide continuity of case management, surveillance, and communication, not usually available from even the best police departments [40,44]. Considering that the primary role of the private police sector is crime prevention [20], PIs can provide law enforcement proactive support to prevent crimes at various levels (e.g., local, state, and national levels) if there are opportunities for partnership [28].

Collaboration PIA–LEA. There is very limited literature on LEAs’ collaboration with PIAs for investigations [21,23,27,40,41]. Based on data from a sample of 377 police officers in South Korea, Lee and Yun [23] found that officers were more likely to collaborate with PIs if they perceived that there were more benefits than costs involved in a partnership with PIs. Likewise, in a survey of 362 participants, Paek, Nalla, and Lee [41] examined police officers’ perceptions of their partnership with PIs in policing cyberspace in South Korea. They found that officers’ perceptions of the seriousness and the frequency of cybercrimes, their computer proficiency, and their training level were positively associated with their support for partnership with PIs. In addition, the number of years of experience was negatively related to police support for any partnership with PIs. Sarre and Prenzler [27] found that LEAs in Australia have collaborated with PIs to investigate crimes in a few ways, including discussion forums; joint investigations; neighborhood-watch-style meetings; joint taskforces; crime-stoppers-style hotlines; and vendor–supplier relationships. Overall, the literature shows a few instances in which law enforcement partnered with PIs when they found there were more benefits than costs [23]. Human trafficking could be another area where law enforcement may find interest in developing investigation partnerships with PIs.

1.4. PIs’ Potential for Human Trafficking Investigations

Exploring factors affecting citizens’ likelihood of hiring PIs to resolve their criminal and/or civil matters, Leea, Leea, Choib, Leec, and Hong [50] found that citizens’ desire for personalized justice was the most significant factor affecting the likelihood of hiring PIs. They also found that citizen’s satisfaction with investigations by the police was negatively related to the likelihood of hiring PIs for criminal cases. According to Mahon [43], “The PI is often the last hope for many people,” (p. 17) to rescue their loved ones from risky situations such as kidnapping or human trafficking. There have been instances where the police have ignored families’ suspicion of a human trafficking incident or viewed it as a prostitution or runaway child situation [51,52]. As a result, people have sometimes hired PIs to supplement investigations carried out by law enforcement or to conduct their own investigations and recovery operations [50,53].

On behalf of families, PIs have often helped monitor online sex trafficking sites, and social media sites of missing children and then have set up surveillance and brought in the police to make arrests and save trafficking victims [48,53]. Time is a decisive factor in searching for and recovering potential victims of human trafficking [48]. PIs can spend as much time as necessary to find victims in such situations because, as mentioned above, they tend to focus on single investigations. Very often, the police have difficulty conducting investigations in some communities because they are feared for their use of force and criminal approaches to obtain information [1]. In contrast, thanks to their versatile skills in interviewing, gathering evidence, conducting surveillance, building trust with key contact persons in a target, and using a victim-centered approach, PIs are likely to find facts that can be crucial in a hidden crime such as human trafficking. Dottie Laster, a veteran female PI, argued that PIs have the distinctive capacities to complement law enforcement’s efforts in human trafficking investigations [53]. “They [PIs] can fill in gaps that law enforcement can’t do,” she said [53] (para.3). She explained that PIs’ skills in finding missing persons and runaways and conducting covert/overt surveillance are crucial in investigating a hidden and moving crime such as human trafficking. She described cases of trafficking investigations she completed before referring them to the police for victim recovery and trafficker arrests. However, knowledge related to the work of PIs about human trafficking is primarily found in the grey literature, i.e., [48,53,54,55]. In his article titled, Inside Human Trafficking Investigations [56], Matt Blumenthal, a deputy sheriff in the San Diego County Sheriff’s Department, stated that law enforcement “face several challenges when taking on human trafficking investigations—time, money, manpower, along with countless search warrants for social media and technology (cell phones),” (para 5). PIs could help limit the challenges LEAs often face in human trafficking investigations.

Hounmenou and O’Grady [57] is arguably the only study that has explored PIs’ experiences in human trafficking investigations. PIs’ strengths identified in the findings include victim-centered interview skills, the capacity to build trust with victims and ethnic communities that fear or distrust the police, surveillance expertise, the ability to focus on single cases, and the capacity to deploy personnel and rely on networks across state and international borders, etc. The agencies of 39 of the 81 participants in that research not only conducted human trafficking investigations but also had human trafficking as a major service area. The types of human-trafficking-related services the PIAs provided within the last five years include: recovering human trafficking victims; assisting law enforcement with human trafficking investigations; tracking human trafficking activities on the Internet; providing witness protection in trafficking investigations; tracking and disrupting human trafficking networks; and testifying in court for human trafficking prosecutions [57]. The PIAs recovered 36 trafficking victims on average (SD = 24) within the five years before the study. Approximately 52% of the agencies recovered minor victims under the age of 18 and 48% recovered adult victims. The findings show that 64% of the victims recovered by the PIAs were citizens of the countries where the study was conducted and 36% were non-citizens. PIAs received requests or referrals for human-trafficking-related services from three sources: victims’ families; people in PI’s networks such as former clients, attorneys, church leaders, or community leaders; and people who had found out about PIAs’ trafficking investigation services online. That study provides important background knowledge for the current study that examines PIs’ experiences and perceptions of collaboration with law enforcement for human trafficking investigations because both studies are based on the same dataset.

2. Methods

2.1. Research Design

A mixed-method design, including a survey and an interview, was used. Purposive sampling was used to recruit the participants. The Google search engine was utilized to gather lists, websites, and contact information of PIAs and associations of PIAs in the 50 U.S. states; the online directory of the World Association of Detectives (W.A.D.) was also accessed for information about PIs and associations of PIAs both inside and outside the USA. The search consisted of three stages.

First, the Boolean search strategy and the modifiers AND, NOT, and OR were used with the following keywords and phrases to find lists and directories of potential participants: private investigator, directory, association, investigation specialist, private police, security services, private detective, and independent detective. Second, the accessed online lists and directories were systematically filtered for PIAs with specialties linked to two groups of keywords: (1) missing persons, locating persons, kidnapping, skip tracing, surveillance, employment fraud, identity theft, and rescue operations; and (2) human trafficking, labor trafficking, labor exploitation, sex trafficking, drug addiction, domestic violence, prostitution, mail bride, sexual exploitation, online exploitation, sexual abuse, runaway, etc. Following this filtering, the e-mail addresses and/or phone numbers of 400 PIAs in 39 U.S. states and five other countries, including Canada, Australia, England, France, and Germany, were collected. Third, the leaders of the 400 PIAs were contacted by phone and/or e-mail to inform them about the research project and asked them to designate one spokesperson for their agencies to participate in the study.

Yet only 360 PIAs were successfully reached, whereas 40 were not for two reasons: invalid e-mail addresses and phone numbers out of service. Thus, the following three criteria were used to select a survey participant from each of the PIAs successfully reached: (1) being a PI whose agency is a member of an association of PIAs; (2) being specialized in services for missing persons, skip tracing, surveillance, rescue, child sexual exploitation, human trafficking, or related issues; and (3) having at least two years of experience as a PI.

A subsample of the survey participants was selected for the follow-up interview component of the study through a screening question in the survey questionnaire. The four criteria of selection for interview participants included: (1) selecting ‘YES’ to the screening question at the end of the first section of the survey questionnaire asking participants if the agency had carried out any human trafficking work; (2) completing the second section of the survey, which was for participants whose agencies were experienced in carrying out human trafficking work; (3) answering ‘YES’ for participation in a follow-up interview to discuss their agency’s experience of human trafficking work; and (4) providing a preferred e-mail address or phone number at the end of the survey to be contacted for an interview.

2.2. Data Collection

The online Qualtrics XM survey program was used to collect data with the survey questionnaire, which was password-protected and self-administered. An e-mail with a unique survey link per organization was sent to each of the leaders of 360 PIAs to have one designated spokesperson complete the questionnaire. Thus, each PIA had only one participant. To increase the response rate, two reminder e-mails were sent to only participants who had yet to complete the online questionnaire a week and two weeks after the first e-mail.

Eighty-one of the 360 PIAs contacted in the USA, Canada, and Australia each had a participant complete the online survey. The 81 participants included: (1) 42 participants who were screened out at the end of Section 1 of the survey after they had indicated that their agencies did not conduct any human trafficking-related investigations and (2) 39 participants who completed both Section 1 and Section 2 of the survey. While Section 1 focused on participants’ demographics, work experience, and knowledge of human trafficking, Section 2 focused on PIAs’ work experience with human trafficking investigations and their experiences and perceptions of collaboration with law enforcement conducting this work. The findings from Section 1 of the survey have been published (see [57]).

Thirty-three of the 39 respondents who completed both sections of the survey agreed to participate in a follow-up, semi-structured interview via Zoom or phone. However, only 28 of these 33 participants were successfully interviewed, and the other five could not be interviewed due to time constraints. The 28 interview respondents included 26 in the United States, one PIA in Canada, and one PIA in Australia. The semi-structured interview guide helped to collect data on the following variables: PIAs’ experiences of interagency collaboration with LEAs; perceptions on the importance of interagency collaboration between PIAs and LEAs; perceptions of challenges for interagency collaboration with LEAs; and recommendations about initiatives of partnership with LEAs regarding human trafficking investigations. Twenty of the interviews were conducted via Zoom meeting and eight were conducted by phone. Each interview took 40–50 min to complete. The research project was reviewed and approved by the Institutional Review Board of the researchers’ university. All of the participants gave informed consent to both the survey and interview components. The survey data were downloaded from Qualtrics XM into the SPSS 20 data analysis program.

2.3. Data Analysis

Descriptive statistical analyses, consisting of univariate and bivariate analyses of the data collected from the 39 participants who completed both Section 1 and Section 2 of the survey, were conducted. Thematic analysis of the data collected from the 28 respondents in the follow-up interview was conducted. The Atlas.ti 8 program was used to code and analyze the interview data. The following seven variables from both the survey and from the interview were analyzed for the present article: (1) level of collaboration of PIAs with LEAs for investigations; (2) participant perception of difficulty for PIAs’ collaboration with LEAs for investigations; (3) participant perception of the importance of LEAs’ assistance for investigations conducted by PIAs; (4) participant perception of the importance of PIAs’ assistance for investigations conducted by LEAs; (5) having collaborated or not with LEAs on human trafficking investigations; (6) frequency of PIAs’ collaboration with LEAs for investigations; and (7) PIAs’ potential skills and strengths crucial for investigations.

Twelve themes emerged from the coded data. Peer debriefing and member checking were used to ensure the accuracy and credibility of the thematic analysis of the interview data. Two research team members separately coded, reviewed, and discussed the interpretation of their findings to ensure the credibility of the coding. To check for the accuracy of the findings, parts of the analyzed data were reviewed by five respondents and revised as necessary.

3. Results

3.1. Participant Characteristics

Table 1. Survey participants’ demographics *.

Variables (N = 39)	Frequency	Percent
Gender
Male	29	74.4
Female	10	25.6
Total	39	100.0
Age (M = 59.6, SD = 11.3)
Age 22–30	1	2.6
Age 41–50	5	12.8
Age 51–60	11	28.2
Age 61–70	17	43.6
Age 71–80	4	10.3
Age 81–90	1	2.6
Total	39	100.0
Number of years as a PI (M = 23.8, SD = 14.5)
1–5 work years	5	12.8
6–10 work years	5	12.8
11–15 work years	3	7.7
16–20 work years	3	7.7
21–25 work years	5	12.8
26–30 work years	5	12.8
31–35 work years	2	5.1
36–40 work years	8	20.5
Over 40 years	3	7.8
Total	39	100.0
Current PI position in the agency
Owner and Senior Investigator	22	56.2
CEO/President	5	12.9
Director/Managing Director	5	12.9
Chief Investigator	5	12.9
Field Investigator	2	5.1
Total	39	100.0
Profession before becoming PI
Law enforcement officer	19	48.7
Intelligence services agent	5	12.8
No prior profession	5	12.8
Security consultant	4	10.3
Armed forces agent	4	10.3
Insurance/paralegal agent	3	7.7
Bodyguard/security officer	2	5.1
Total	39	100.0

* Adapted from Hounmenou and O’Grady [57].

displays the demographic characteristics of the subsample of 39 survey participants. Twenty-nine (74%) participants self-identified as male and 10 (26%) self-identified as female. Most of the participants (n = 17; 44%) were between 61 and 70 years old (M = 59.6 years; SD = 11.3). Before becoming PIs, approximately half the number of participants (n = 19; 49%) used to be law enforcement officers (i.e., including FBI special agents and police officers from city and state law enforcement departments), while 9 (23%) had worked in intelligence services or the armed forces. Most of the participants were in senior management positions inside their agencies. While 22 participants (56%) reported being the owners and senior investigators of their agencies, 5 (13%) reported being the CEO/presidents of their organizations and 5 (13%) reported being directors. On average, the participants had been PIs for 24 years (SD = 14.5).

The survey subsample of 28 interview respondents in the present study included eight (29%) PIs who self-identified as female and 20 (71%) who self-identified as male. Eighteen of these respondents (64%) were former law enforcement officers. Two of the thirty-nine PIAs were nonprofit organizations and Thirty-seven were for-profit organizations. On average, the PIAs have existed for 23 years (SD = 17.2). Many agencies provided services at multiple geographical levels, including (60%) at a state-wide level, 45% at the national level, and 16% at the international level.

3.2. Experiences of Collaboration between PIAs and LEAs for Human Trafficking Investigations

Using the same dataset as the present study, Hounmenou and O’Grady [57] provided details about PIs’ skills and experience in investigating human trafficking cases. The findings below focus on PIs’ experience of collaboration with LEAs for human trafficking investigations.

3.2.1. Frequency of Collaboration between PIAs and LEAs for Human Trafficking Investigations

On a five-point Likert scale ranging from 1 ‘never’ to 5 ‘always’, the survey participants’ perception was sought about how often PIAs and LEAs, in general, collaborate on human trafficking investigations. As shown in

Table 2. Survey participants’ knowledge and perceptions of PIAs’ collaboration with LEAs.

Variables (N = 39)	Frequency	Percent
In your opinion, how often do private investigations agencies and law enforcement agencies (i.e., police departments, sheriff’s office, FBI, U.S. Marshals Services, etc.) collaborate on human trafficking investigations? (M = 2.42; SD = 0.68)
1 = Never	1	2.6
2 = Rarely	23	60.5
3 = Sometimes	11	28.9
4 = Often	3	7.9
5 = Always	--	--
Total	38	100.0
How would you rate collaboration between private investigations agencies and law enforcement agencies on human trafficking investigations? (M = 3.51; SD = 1.17)
1 = Not difficult	1	2.7
2 = Slightly difficult	6	16.2
3 = Somewhat difficult	14	37.8
4 = Moderately difficult	5	13.5
5 = Very difficult	11	29.7
Total	37	100.0
How would you rate law enforcement agencies’ help for human trafficking investigations conducted by private investigations agencies? (M = 3.35; SD = 1.47)
1 = Not important	4	10.8
2 = Slightly important	11	29.7
3 = Somewhat important	2	5.4
4 = Moderately important	8	21.6
5 = Very important	12	32.4
Total	37	100.0
How would you rate private investigations agencies’ help for human trafficking investigations conducted by law enforcement agencies? (M = 3.64; SD = 1.41)
1 = Not important	4	11.1
2 = Slightly important	5	13.9
3 = Somewhat important	5	13.9
4 = Moderately important	8	22.2
5 = Very important	14	38.9
Total	36	100.0
Has your agency ever collaborated with any law enforcement agencies on human trafficking investigations?
Yes	28	73.7
No	10	26.3
Total	38	100.0
How often has your agency collaborated with law enforcement agencies on human trafficking investigations? (In number)
Collaborated with LEA 1–5 times	18	64.3
Collaborated with LEA 6–10 times	6	21.4
Collaborated with LEA 11–20 times	4	14.3
Total	28	100.0

, most of the participants (n = 23; 61%) selected 2 to indicate their perception that PIAs and LEAs ‘rarely’ collaborate for human trafficking investigations, while 11 participants (29%) selected 3 ‘sometimes’ (M = 2.42, SD = 0.68).

The survey participants were then asked whether their agencies collaborated with LEAs for any human trafficking investigations. Of the 38 participants who responded to this question, 28 (74%) answered ‘yes’, and 10 (26%) responded ‘no’, (Table 2). The 28 participants who responded ‘yes’ were then asked about the frequency of collaboration their agencies had with LEAs on human trafficking investigations. Of these participants, 18 (64%) indicated their agencies collaborated with LEAs 1–5 times’, six (22%) indicated ‘6–10 times’, and four (14%) indicated ‘11–20 times’.

3.2.2. Extent of Collaboration between PIAs and LEAs

The findings show that the agencies of 20 of the 28 interview respondents collaborated with LEAs for human trafficking investigations they conducted. As mentioned in the literature review, they provided several types of human trafficking-related services, including trafficking victim recovery; assisting law enforcement with trafficking investigations; tracking human trafficking activities on the Internet; providing witness protection during trafficking investigations and prosecutions; tracking and disrupting human trafficking networks; and testifying in court for trafficking prosecutions. There are varying responses regarding the extent of their collaboration with LEAs. Some PIAs collaborated with LEAs on a consistent basis. For instance, S.R. stated, “We collaborate with law enforcement almost on every investigation that we work on, but it wasn’t easy to get to that point.” Likewise, K.S.’s agency successfully collaborated with LEAs due to her prior background in law enforcement:

Pretty well, because I am a former law enforcement officer. I do cooperate with the police if I have some questions, I know who to go to, and who to talk to, and if I have some human trafficking going on, I get their cooperation too, and I give them my information. I don’t think they’re hesitant towards me or the human trafficking cases I work with.

K.S.’s easy access to LEAs for partnership on investigations her agency initiated appeared to be due to her past career in the FBI before she became a PI. Thus, law enforcement experience helps PIs establish connections with the police and share information with them. Thanks to their law enforcement experience, some participants understood the importance of sharing criminal investigation information with the police. However, the extent of collaboration between PIAs and LEAs depends on the state or country where a PIA is located. The findings show that LEAs in states such as New York and New Jersey appeared receptive to collaboration with PIAs. LEAs’ openness to partnering with PIAs also depends on the state laws governing PI’s profession and work with LEAs. Discussing his PIA’s experience of partnering with LEAs, T.S. stated,

Well, we worked exclusively with different organizations of law enforcement organizations when I was operating in New York, mostly on federal and state levels, for that matter, and the local level area of deputy sheriffs. We were able to collaborate with the state and the federal government where we actually had resources that we could make referrals by telephone.

However, some interview participants were unsuccessful or had never collaborated with LEAs. There are varying perspectives on opportunities or the need to collaborate with LEAs. Seven of the respondents reported having tried to collaborate with LEAs, even to volunteer to help with ongoing investigations by LEAs, but in vain. Such rejections were more pronounced among PIs without or with limited connections with LEAs than those who were retired law enforcement officers or those who had an extensive network inside the circle of LEAs. C.M., who has been a PI for over 30 years, found no need to collaborate with LEAs:

There’s never been a need for me to because I’ve been hired by families and private clients. I think the only real circumstance where I would use law enforcement is if I need to do what we refer to [as] a dynamic entry into a building. But other than that, I wouldn’t want to involve law enforcement because I think that it would reduce my chances of recovering a victim successfully.

C.M.’s point above suggests that PIs would avoid reaching out to the police when they knew or believed the police would arrest trafficking victims and treat them as criminals. In situations with serious violence risks, some respondents said they could consider asking for law enforcement support so long as there was an understanding that the clients being recovered would not be arrested.

3.2.3. Successful Interagency Collaboration between PIAs and LEAs for Human Trafficking Investigations

Eight respondents reported having successfully collaborated with LEAs on many human trafficking investigations. While all these respondents described investigations of sex trafficking cases they conducted, only three participants discussed investigations of labor trafficking cases. For instance, T.S. reported that his PIA successfully collaborated with law enforcement at both state and federal levels for labor trafficking investigations. Describing one successful investigation of international labor trafficking his agency conducted in collaboration with law enforcement, he said:

One of the labor trafficking cases that we worked on in our investigations culminated in a successful prosecution of a labor trafficker. A school district in upstate New York had hired a general contractor who, in turn, hired a subcontractor whose bid came in significantly lower than the local area economy dictated. So, we were asked to investigate the subcontractor, who happened to be from New York City. Through the course of on-site interviews and videotaping and monitoring of the project, we learned the workers were all undocumented immigrants being housed together. They weren’t being paid proper rates, and some of them weren’t being paid at all. We documented the case and referred it to the New York State Police and to the General Attorney’s Office. The state ultimately prosecuted the contractor for labor trafficking and gained repayment for wages to the workers who were grieved. There are a number of those kinds of cases that we’ve worked on through the years.

This respondent reported that his PIA successfully investigated at least two dozen labor trafficking cases. His agency’s success in labor trafficking investigations resulted in sustained collaboration with LEAs across New York State. As he explained:

We had monthly meetings with law enforcement representatives from different counties, states, and government officials and we’ve developed these relationships with our community and their community. We discussed how we were going to approach cases, what cases were on the rise, how we felt, what we need to get better addressed, and what they needed to get better addressed.

A.S. described another investigation of a labor trafficking case his agency collaborated with LEAs on:

We were conducting a counterfeit product investigation and the merchandise was being sold in a flea market. As we conducted and concluded our investigation, we realized that the folks that were working in their booths selling were more than likely folks that were human trafficked, brought into the country specifically to do the work for the folks that owned and ran that enterprise. So, once we determined these folks aren’t really doing this voluntarily, we then notified the Vice Unit of the Metropolitan Police Department. They handled the rest of the human trafficking investigation based on the information that we had turned over to them. Yet, I don’t honestly know the outcome of the investigation because it was turned over to law enforcement.

D.L., a female PI with 17 years of professional experience, described a successful case of investigation and recovery of a labor trafficking male victim that she conducted across the U.S.–Mexico border yet without collaborating with the police department that was supposed to investigate the case but did not:

One case that comes to mind is one man, very brilliant, who was missing for weeks. He was taken to Mexico, missing for weeks when we got the call on day 18, and I had him home by day 21. The police had not even responded yet; they responded the day after we got him home. I did a lot of Internet and phone investigations like the old style. Calling neighbors, looking at maps. And I found out it was a drug cartel keeping him, and I figured out where their safe house was. I went to their safe house and I told them, ‘I will never leave this house until that young man is home’, and I had a very big scary guy with me. I got the victim home that night. The way that they targeted him was that he was working in a nearby gym and they became friends with him and helped him build up his muscle and get stronger and bigger; then they lured him to be a controller in one of their brothels in Mexico. That was a U.S. citizen.

This case of investigation that D.L. reported, if verified, could have put herself and the male victim she recovered in a deadly situation, especially because it was related to a drug cartel and in another country. As stated above, collaborating with LEAs for any human trafficking investigations was emphasized as very important by most respondents.

However, according to most respondents, in any instances of collaboration initiatives with LEAs, only the latter received credit in the media and their department for the successful human trafficking investigations that had PIs collaborated on. According to B.E., the frustration and difficulty for PIs to conduct human trafficking investigations have to do not only with the refusal of law enforcement to assist PIs in the recovery of victims in dangerous situations but also with their reluctance to acknowledge the vital information that PIs had shared with them. D.L. reported that she collaborated a few times with LEAs but obtained no recognition for her contributions. She claimed that she received no recognition for her significant input in a major trafficking investigation in collaboration with an LEA, which resulted in the arrest of about 140 people involved in a trafficking ring. As she stated, “The agency got the FBI’s highest honor, but it was never attributed to me or my work. And sometimes that’s good. It’s not a criticism. I do not want the credit for getting 140 arrests.”

3.3. PIAs’ Potential Contributions to Human Trafficking Investigations Initiated by LEAs

The 39 survey participants were asked about their perception of how important PIAs’ assistance could be in human trafficking investigations conducted by LEAs. Most participants (n = 14; 39%) selected 5 to indicate that PIAs’ assistance could be ‘very important’, and eight participants (22%) selected 4 to indicate it could be ‘moderately important’ (M = 3.64, SD = 1.41). These findings indicate many participants’ perception that PIAs’ input in human trafficking investigations conducted by LEAs could be crucial. There was a significantly positive and strong relationship between the variables “PIAs’ support for investigations by LEAs” and “LEAs’ support for investigations by PIAs,” r = 0.62, p < 0.01 (

Table 3. Correlation of scales assessing perceptions of collaboration between PIAs and LEAs about human trafficking.

	Variables	M	SD	1	2	3	4
1	Perception of collaboration between PIAs and LEAs.	2.42	0.68	1
2	Difficulty in collaboration between PIAs and LEAs.	3.51	1.17	−0.490 **	1
3	LEAs’ support for investigations by PIAs.	3.35	1.47	0.092	−0.365 *	1
4	PIAs’ support for investigations by LEAs.	3.64	1.41	−0.026	0.008	0.616 **	1

**. Correlation is significant at the 0.01 level (2-tailed). *. Correlation is significant at the 0.05 level (2-tailed).

). The results suggest that PIs’ perception of difficulty in collaboration between PIAs and LEAs depends upon their level of perception of any collaboration between the two sides.

Corroborating the survey findings, the interview respondents discussed the contributions PIs could make to investigations of trafficking cases initiated by LEAs. The following sub-themes were identified from the data: the openness of PIs to cooperate with LEAs; providing training to LEAs about human trafficking; getting people to collaborate with LEAs; conducting interviewing with hard-to-reach witnesses; conducting surveillance support for LEAs; collecting intelligence and sharing information with LEAs; and the capacity to a make citizen’s arrests.

3.3.1. PIs’ Disposition to Cooperate with LEAs

Seventeen of the twenty-eight interview respondents, especially veteran PIs, reported not having much difficulty reaching out to LEAs. They informed or partnered with LEAs on almost all cases of human trafficking they investigated. Yet, most of these participants acknowledged that, very often, they had to overcome difficulties in getting LEAs to carry out their part of the work, meaning intervening to recover victims and arrest potential traffickers. As M.M. stated, “I don’t have many issues to deal with law enforcement that I have to overcome. They have to overcome difficulty with working with a non-law enforcement person.” The respondents reported having had many cases of sex trafficking investigations where they partnered with LEAs, in which the victims were arrested and charged with crimes. Thus, in efforts to prevent law enforcement from treating their clients as perpetrators of trafficking crimes, before collaborating with LEAs, some PIs would ask LEAs for a formal agreement for the immunity of trafficking victims they were hired to recover. As C.M. explained,

I think the biggest thing that they [LEAs] can do, if they could promise me that if I’m pursuing the victim and they’re not going to arrest the victim, and that they could put something in writing because I need more than a handshake from them or the DEA.

3.3.2. Providing Training to LEAs for Human Trafficking Investigations

The findings show that PIs who are human trafficking experts provide training to LEAs in many U.S. states. Seven of the twenty-eight respondents reported having trained hundreds of officers. Law enforcement experience in vice and drug units and human trafficking task forces, added to extensive practice in private investigations, enhanced the expertise of some of the participants in this study, which allowed them to train officers on trafficking investigations. As described above, half of the PIs in this study were retired law enforcement officers, including special FBI agents who had worked in vice units or human trafficking task forces; three were army veterans. C.C., a retired FBI special agent, reported being the lead expert on an anti-trafficking statewide task force and provided training to hundreds of officers in her state. S.R., another respondent, reported having provided training to approximately 2500 law enforcement officers on investigating human trafficking cases. He had been in federal law enforcement before establishing his PIA for over 20 years by the time the present study was conducted. Discussing his experience of training officers, he explained,

They [police officers] don’t get that type of training at the academy, and they don’t get it at their office. My training is post-certified; law enforcement has to have 40 h of training throughout the year, and the block of instruction we offer is free to them. We train them on what to look for, and what websites to go to because a lot of these websites that these victims are advertised on, don’t know.

3.3.3. Serving as Intermediaries between Families and LEAs

The respondents discussed how PIs are intermediaries between LEAs and families or communities that need help to find members that may have fallen victim to human trafficking. The respondents perceived that one of the great advantages of PIs is that they can gain victims’ families’ trust more quickly than law enforcement. Interestingly, three female respondents argued that being a female PI was a great advantage in getting family members to share information that could help investigate human trafficking and missing person cases. To illustrate how helpful it was to be a female PI, K.H. said,

I mean, there’s quite a few ways. One, I’m in plain clothes, I am not law enforcement and getting someone to talk to law enforcement and I am someone who looks like a mom, all that can make a huge difference in getting a name, a location, who a victim’s friends are, etc. So, I think that’s one aspect is that we are not an authoritative figure that police are and people are not scared to talk to us. I am a mom and I can talk to people and they don’t expect what I do and people are more trusting of a female to give them information about their neighbors or all that kind of stuff. I do think it is an advantage.

C.A., another female PI, discussed how she often served as an intermediary to LEAs during investigations:

One of the things law enforcement has used me to do as well is sometimes being a go-between with family members. Some mothers can be super manic. Like I had a case in California where the mom was just a wreck because her child was being trafficked. Her boyfriend was trafficking her daughter. So, the police have me basically case managing with the mother, so she’s not bothering the police. I know the police appreciate my help. I’ve had a few detectives who have said really kind things about me and even referred private cases to me.

3.3.4. Locating Missing People, Gathering Intelligence, and Conducting Surveillance

The respondents argued that PIs are most competent in locating missing and trafficked persons and conducting surveillance support for LEAs. Though they have substantial funding, LEAs do not have the manpower and the time necessary to investigate cases of human trafficking adequately. As J.K. argued,

We can do all the skip tracing; we can do the locating and the leg work. The police don’t have the resources. If there is a special victim’s unit, I think we can help them and tip them off eventually.

In the state of T……., only three law enforcement agents worked on human trafficking. “So, they often will call us if they don’t have the resources to do surveillance and ask us, ‘Can you guys assist us on surveillance and tell us what you think?’” said S.R., who managed a big trafficking-focused investigation agency.

The respondents reported that sometimes people are leery of speaking to LEAs. Thus, one advantage PIs have, which can be important for trafficking investigations, is that they are not law enforcement officers. As R.H. observed, “It would assist having somebody who is not law enforcement, who has the skills and the training, and the experience to do what law enforcement does. That’s what a PI can contribute to law enforcement, another asset in their toolbox.” T.S. stressed another advantage for PIs, that is, being accessible to and familiar with people in the local communities where they work:

We are familiar with the ins and outs of the way a business operates, we’re familiar with the specific areas within our geographical region, some cases in states you don’t know where necessarily to go or who to talk to, and I think that us as part of the community we are able to know who the players are.

The respondents also reported that PIs have access to information without any legal hurdles, contrary to law enforcement officers. For instance, R.H. explained,

There is information that I can get, and I can get it legally, and I don’t need a subpoena because we get our information from different sources. So, we can cooperate with them [LEAs] not only with the actual case in the investigation but also with our sources of information and our assets. This is what we can contribute.

However, some respondents reported being frustrated when LEAs would refuse any help PIs volunteered to offer them or would show selfishness when soliciting assistance from PIs. It was interesting to find that one way to get law enforcement to trust a PI and seek their help is only when the PI has vital information on an investigation and has shared it with law enforcement. Thus, once the police realize a PI has good contacts and the know-how to gather valuable information, they want to work with them, but in only one direction and on their own terms. C.L. explained that,

They still are not going to tell you their secrets, but they want you to tell them what you know. When you tell them something, and they find out it’s the truth, they will go back to you immediately and ask you for other things because you have already proved once or twice that the information you have is the truth.

The respondents reported that being a PI can give you some leverage and shortcuts you can use because you are not bound by the law as much as police officers. M.H. explained that PIs do not have to follow the rule of statutes, subpoenas and summonses to obtain information. They can go out and ask questions. Summarizing the shared view among participants about ways PIs could enhance investigations of human trafficking cases, one respondent observed,

The police are not winning the war against human trafficking. However, if they start working with PIs, then they would probably catch more human trafficking perpetrators. What they would be getting from PIs would be additional expertise, additional sources, and actually a different viewpoint on how to approach investigations.

3.4. LEAs’ Potential Contributions to Human Trafficking Investigations Initiated by PIAs

The 39 survey participants were asked about their perception of the importance of having LEAs’ assistance for human trafficking investigations conducted by PIAs, on a scale ranging from 1 ‘not important’ to 5 ‘very important’, (Table 2). Most participants (n = 12; 32%) selected 5 to indicate that LEAs’ assistance is ‘very important’ and 11 participants (30%) selected 2 ‘slightly important’, (M = 3.35, SD = 1.47). The findings suggest that LEAs have a key role to play in human trafficking investigations conducted by PIAs.

3.4.1. Importance of Reaching Out to LEAs for Human Trafficking Investigations

Despite various challenges when reaching out to LEAs for help in investigations, 10 of the 28 interview respondents emphasized the importance of collaboration with LEAs. Confirming this point, E.W. discussed how he would often refer his cases to LEAs for criminal investigations:

If someone hired me because they suspected their daughter was involved in human trafficking, for example, and we found evidence to indicate they were, the next step would be to get a criminal investigation going, which we’re not able to do. We would have to get law enforcement involved.

Though he liked collaborating with LEAs, E.W. acknowledged that the level of cooperation with LEAs often depends upon your connection with officers and the type of investigation you are conducting. Yet, some participants only had negative experiences trying to partner with LEAs. There was a shared view among all the respondents that cooperation with LEAs highly depends on the PI’s network capacity and size. As J.S. stated,

Unless you have personal contact with law enforcement, forget about them assisting you. Now, most, if not, all PDs require you to file some sort of report before they investigate the matter, and in all cases, a PI is not the victim, so they can’t file a report.

Nevertheless, many respondents agreed that collaboration between LEAs and PIAs could play an essential role in any successful investigations. They stressed the importance of proactively networking with LEAs. As B.W. shared,

As a PI, you can’t wait until you need assistance from law enforcement and then go in and expect that assistance to go over. You have to go proactively before you have any cases and develop that relationship, you need to go in and talk to law enforcement on the local level. If you develop those relationships upfront and don’t wait until you need their assistance, you can be way more successful.

K.R., a seasoned PI, discussed how his agency was successful in solving a trafficking case by reaching out to law enforcement and letting them know ahead of time about the ongoing investigation:

You need to reach out to law enforcement to let them know that you have something so that there’s already Intel and they already have someone assigned to contact and so we literally were able to get them on site within three hours after the initial call.

The respondents stressed the importance of making efforts to develop collaboration with LEA despite the latter’s resentment. As B.L. said, “The important thing is just working with law enforcement and not against them.”

Almost all of the respondents discussed the crucial role of LEAs in criminal investigations because they have the legal powers to arrest and prosecute perpetrators. A.S. explained,

We could generate a lot of information that they could use, but they are going to be the ones that are handling the filing of the criminal case and all that, so ultimately, I mean I would say they are very important because if it’s a criminal thing they are going to take care of that.

Likewise, many respondents believed that LEAs need PIs in criminal investigations because the latter could perform the groundwork required to make arrests and gather information about victims and suspects.

3.4.2. Sharing Information and Resources with PIAs

At least 20 of the 28 respondents concurred that LEAs should share information from their plethora of databases with PIs, who rarely have access to these resources. B.K. explained,

In some instances, I would say some PIs might be at the end of their rope as far as finding out information on individuals, and it would be great to collaborate with law enforcement to say, ‘Hey, this is who I am investigating, I think that they might be connected to this person or this other person and into this activity, can you look these people up in these systems to help me out?’

However, there are varying opinions on whether PIs need LEAs’ databases to find background information for their investigations. While some PIs may not need access to LEAs’ databases or resources for their investigations, most participants pointed out the necessity for building partnerships between LEAs and PIAs for successful investigations. As B.W. stated,

It is imperative that there is close coordination between PIs and law enforcement for these cases to be successful. We have to work hand in hand, we have certain abilities that they do not have, law enforcement has a jurisdiction area and they can’t go outside of that jurisdiction; we can, we can go outside of a jurisdiction to continue an investigation somewhere else. But they also have the ability to subpoena and the ability to run cell phone traces and things of that nature, so it needs to be a collaborative effort for successful completion of a case because we don’t have all the tools that they have and they don’t have all the tools that we have.

In contrast to PIs in Australia and Canada, a few PIs in the U.S. had a better experience collaborating with LEAs. However, D.L. advised that PIs should utilize LEAs as a tool to be used at the right time. She explained her point, stating,

I don’t often count on police; I use them as one of my many tools. I don’t let them be the first part of the case, and I develop many human trafficking task forces with law enforcement; so, I’m knowledgeable of who and which agency to use for what. So, I use them in that way… Only when it’s time to investigate for the purpose of prosecution is the time to start using them as a tool in the case.

As stated above, a recurrent issue with collaborating with LEAs is that they will ask for PIs’ information but will not share any information. M.P. emphasized this biased poor communication and dynamic between PIAs and LEAs:

… If you are stuck and you go to the police, they are not going to give you their information and there is no help unless when they see that you are a paid agent from the family member or whatever, then they will ask you for a lot of information they cannot find by themselves… So, they will use your information to get their file complete… they may talk to you, but they will give you all the information they want to give, not the accurate information.

3.5. PIs’ Perception of Challenges for Collaboration with LEAs for Human Trafficking Investigations

The survey participants were asked about their perception of the difficulty of PIAs to work with LEAs on human trafficking investigations on a five-point scale ranging from 1 ‘not difficult’ to 5 ‘very difficult’ (Table 2). Most of the participants (n = 14; 38%) selected 3 to indicate their perception that it was ‘somewhat difficult’ for PIAs to collaborate with LEAs, while 11 participants (29%) selected 5 to indicate it was ‘very difficult’ to do so (M = 3.51, SD = 1.17). These findings suggest a shared perception among the participants that PIAs often face challenges collaborating with law enforcement. There was a significant and negatively moderate correlation between the variables ‘Perception of collaboration between PIAs and LEAs’ and ‘Difficulty for collaboration between PIAs and LEAs’, r = −0.49, p < 0.01 (Table 3).

Challenges to collaboration between PIs and law enforcement can be highlighted through the following subthemes from the interview data: LEAs’ resistance to information sharing; law enforcement’s culture of distrust with PIs; law enforcement’s selfishness and feeling of power; and legal issues with law enforcement sharing information with PIs. Corroborating the survey findings above, the interview findings show that LEAs dislike partnering or cooperating with PIs and often prefer not to have a working relationship with the latter. Ten interview respondents mentioned LEAs even questioning the credibility of PIs’ legitimacy and skills. As J.S. explained:

Obstacles and challenges are many. First that private investigation is not a political entity and is a business, and the purpose of a business is to make money. You can only afford to do so much pro bono work. Second, the police, in most cases, do not like working or taking referrals from private investigators as they view PIs as second-class citizens not the professionals they are. Or the police view your nosing around as interfering with their investigations or informants.

On a similar note, T.S. mentioned how a poor level of interaction between PIs and LEAs contributed to the lack of cooperation:

I think one of the problems that I’ve encountered, particularly in my state, is that there is a lack of interaction between PIs and law enforcement. Law enforcement community in my rural, poor area is not available to have a discussion or for me to make a report or referral about labor trafficking or sex trafficking for that matter.

3.5.1. Law Enforcement’s Culture of Distrust with PIAs

The interview respondents expressed frustration with LEAs for the latter’s disinclination to share information with PIAs regarding human trafficking investigations and recovery of potential victims. The findings show that LEAs’ refusal to work with PIAs was especially strong in countries such as Australia and Canada. K.S., a veteran Australian PI with over 35 years of professional experience, explained, “In Australia, we cannot check a license plate, and law enforcement should provide that information, but they neglect to provide the help… they do not like sharing information. They don’t like PIs doing more than they can do.” On a similar note, R.W., another veteran PI in Canada, who also worked in the U.S. for over a decade, observed,

You just don’t get cooperation from law enforcement to the private sector. Like me, if you ask them questions, they look at you like you’re deaf, dumb, and blind. Eh, like again, my experience is that you come to make the complaint and then you leave it with them because you’re out of the picture.

The respondents agreed that one of the biggest obstacles to collaboration with law enforcement, in general, is related to police culture where police only trust other police, a culture ingrained in police departments, according to some of the respondents. They do not trust PIs and do not believe that PIs have the ability to help them. Seven respondents reported that law enforcement rarely contacts PIs for any investigation, even when they know the latter can assist them. Law enforcement would rather that PIs shared with them information that could help conduct their own investigations. R.T. stated,

Really the only time that law enforcement will be open to cooperating with PIs is two ways. One is if you’re a process server, if you are serving court papers to defendants or plaintiffs, you’re then an extension of the court by doing that. Second, if you happen to get a contract with a state entity, then they know you and come to you for information. Before a law enforcement officer comes out and asks for your opinion or your help, I would say it does not happen unless your name comes up in an investigation.

In the same line of view, C.L. explained,

Cops don’t want other people working alongside them. They want you to give them all the information you have. But they aren’t going to give you any information. In general, police do not like to work hand in hand or alongside PIs on anything, unless they know you.

LEAs like protecting their monopoly over investigations because they perceive they are the only ones to enforce laws. S.R. explained, “Law enforcement has a blinder mentality that they don’t want anyone else working on this than them. I think it was a very hard in-road to get them to trust another organization to work towards an investigation.” Another participant added, “As a PI, your credibility does not matter much for an LEA that does not have any previous interaction with you unless you have some inner connection to the law enforcement department.” T.H. appeared to have a better understanding of law enforcement’s complex of superiority in information sharing:

I think it is very important for law enforcement to collaborate with whoever is willing to help them. But they don’t have the ability to do that, and I don’t know if they would really want to. They don’t like to share; you know they don’t like to entrust things to other people. And they don’t need more work given to them. They don’t look for more crimes.

The findings also showed that it is very difficult to cooperate with LEAs because the inner circles of LEAs themselves are very competitive. As S.L. stated,

You have LEAs that won’t collaborate with each other. So, you have city, county, and state agencies that will not collaborate, and then you have the federal agencies, and everybody is competing against each other, and it makes it very difficult to get a job done.

3.5.2. LEAs’ Self-Centeredness and Feeling of Power Entitlement

Almost all of the 28 interview respondents shared the perception that collaboration with law enforcement is highly affected by other behaviors: selfishness and a sense of power entitlement. C.C. perceived,

Law enforcement has egos that become involved when you have an experienced retired officer who is now a PI and knows how to do the talk. And they approach the law enforcement officer, and he quickly realizes that he or she does not have that experience. So, the ego becomes affected, and that’s the first issue you have to deal with. Then, the second one is the current law enforcement officer saying, ‘You’re trying to tell me how to do my job, this is my job, not your job. You are interfering’, even if they may not have anything going on.

Likewise, B.K. observed, “… When somebody else comes in and tells you something that you didn’t know, the problem is keeping those egos out of the way, and there are a lot of egos in law enforcement.” For B.W., the biggest obstacle to cooperation has to do with personalities, “with individuals not wanting to share information, individuals not wanting to work with another organization that even happens between different LEAs. They tend to get possessive of their information and their investigation.” C.C., a veteran female PI, argued that the pride of a law enforcement officer would be further hurt when she presented herself during training:

There is even a double ego issue against me because I am a female and because they assume when I tell them I’m a retired FBI agent, they assume that I sat at a desk and pushed paper around on a computer and I wasn’t actually out on the field working on violent crime. So, the first thing I do when I present to a law enforcement audience is just give them a little bit of my background that I’ve been on the street and I know what I’m doing and I’ve done this and you can benefit from my experiences.

According to some respondents, due to ego issues, law enforcement would often make errors in investigations because it would be an anathema to take any advice from outsiders about their job. As M.M. remarked,

Many law enforcement officers do their thing, and they think they are right, but they are not right. There have been so many crash reports that I’ve had to change, of course, you can’t get them changed, but you have to show why a crash report isn’t accurate because that investigator didn’t do a good investigation. They don’t like to be told by someone outside their department that they didn’t do it the right way.

It was also reported that it is not only selfishness that affects PIs’ relations with law enforcement, but also a sense of absolute power that the latter are desperate to protect. Interestingly, after retirement and becoming PIs, they too are shocked to experience the same disdain from young law enforcement officers:

Oh, you know it’s a funny weird thing. It’s like when you are in law enforcement, you don’t want to give it out. Everybody thinks that everybody else can’t be trusted, and then they get out and go like ‘Why can’t you trust me?’ They don’t want anybody else to be as powerful as them. It’s kind of the personality of most cops, and it’s become systemic.

Furthermore, not only is there distrust of law enforcement towards PIs but there is also untruthfulness. Some respondents reported that police would not share information with anybody unless they gave you the wrong information in order to get the right information from you. M.P. justified that behavior of the police by stating, “The police don’t care about cooperation with anybody, especially PIs. They want the information, that’s all, no cooperation, no help, no information, nada. That is very important for you to know”.

3.5.3. Law Enforcement’s Lack of Understanding of PIs’ Competencies

The respondents believed that law enforcement has little understanding of what PIs do and what skills they can contribute to investigations. According to T.S., “There might be some mistrust in PIs because they don’t understand what we do or understand why we do what we do, why they don’t do what they do,” It will be very difficult for any PI who is working on an investigation to get any help from a law enforcement officer he/she has never worked with before. According to K.R.:

The biggest obstacle, anytime you do an investigation with law enforcement is their lack of understanding of the private investigation industry. They don’t understand us; all they think we do is cheating spouses, and that’s all. So, they tend not to take us seriously.

Two respondents raised a concern about LEAs being sometimes complacent and negating the existence of human trafficking in ways to cover up, for unknown reasons, criminal activities of trafficking rings. As L.S. stated,

In my experience, we also have people out there who are involved in law enforcement, and who also work for the other side. That makes it very difficult when you are giving them training. They say human trafficking is not going on. And I have been to those trainings where I argued with them, and they said, ‘No, you are absolutely wrong; why you are lying to the crowd right now?’ They become very defensive because they’ve been bought.

The point in the quote above-mentioned by L.S., a female PI who was a retired FBI special agent, could further be explained in two ways. First, an issue of ego among law enforcement regarding obtaining any assistance or lessons from PIs. Second, trainees might resent that the trainer was a female PI, even though she had extensive experience in vice units.

3.5.4. Legal Restrictions to LEAs’ Ability to Share Information

Five respondents, all retired law enforcement officers turned PIs, explained that law enforcement will not or cannot share information with PIs regarding any investigations because of legal barriers. T.H., who retired from Air Force Intelligence and a state law enforcement department, said, “It’s not like they don’t like helping PIs. The reason is that the law doesn’t allow them to work together. They’re able to take whatever information, but not give away any information.” He provided further justification for law enforcement’s behavior:

They like you to make the cases for them, but they won’t cooperate with you to get information that will help you and your investigation because it’s actually illegal to do that. It didn’t use to be so, but it is now. If you have a personal relationship with somebody, they might give you information, but they’re giving you information illegally. Informal, but also illegal. If they got found out, they would be fired at the least.

Actually, some laws prevent law enforcement from sharing information about investigations. As T.H. explained,

There are a number of laws that prevent it, I can’t give you a citation. But for example, in the NCIC (National Crime Information Center) information, it’s illegal for LEAs to provide that to anybody. They have to have a legitimate reason just to inquire for themselves; they can’t inquire into the NCIC system on behalf of somebody else.

In addition, most state jurisdictions in the United States restrict access to law enforcement databases. Any open cases handled by law enforcement are not subject to the Freedom of Information Act. As T.H. said,

So, a lot of times, even if the police close a criminal case, it’s not available under the Freedom of Information Act because even if it’s closed and it’s not been solved, it’s just an appending status, it’s not been resolved; so, it’s still outside the scope of the Freedom of Information and that applies locally, in the state, and federally.

Like T.H., L.S. justified law enforcement’s challenge for sharing information with PIs:

A law enforcement officer cannot share back with us because they are limited in what they are allowed to provide to us, so that’s where the inter-agency collaboration becomes difficult, unless there was some agreement or waiver or if we were hired on a voluntary or contractual basis from the agency itself.

Thus, part of the obstacle to a PIA-LEA partnership is that law enforcement has to abide by regulations on what they can share about their investigations. However, T.H. counterargued that:

Even if those laws were eliminated, the reality is that there’s a great deal of insecurity among law enforcement investigators. For one thing, every investigator thinks he’s the best out there, so he doesn’t like someone else second-guessing what he’s doing. If they open information up to someone from the outside, even from somebody from their own department, they’re often hesitant to share. That exposes them to potential criticism, so they like to keep everything close to the vest.

According to some respondents, PIs too are bound by their professional ethics of privacy and confidentiality about the relationship and information regarding investigations they have conducted on behalf of their clients. For instance, PIs cannot share information with law enforcement without their client’s consent. As L.S. said, “So, as a PI, I can share everything with the law enforcement officer regarding my case as long as my client approves.” Overall, an underlying point most respondents concurred about was that, in their criminal investigations, PIs should avoid obstructing ongoing investigations by law enforcement and keep the latter informed of any parallel investigations they are conducting. This point is well summarized by K.R. stating:

In almost all the cases, on some level, number one, we need to make sure that we’re not stepping on an investigation or sting operation that they’re doing. Then, number 2, we need to make them aware that if we do find any lead, then we are going to need to contact somebody to move in quickly.

To avoid obstructing any LEAs’ ongoing investigation, R.T. advised:

One thing that you have to be very knowledgeable about and to know not what to do is you don’t want to put yourself in a position of obstruction or that, so that if it ever came up with me, what I would do is, you know, go to the state’s DND [not defined], keep them informed of what you’re doing and where you’re going for you to ensure that you’re not stepping on their toes or not interfering with something that you don’t know with what they’re doing. That’s just common courtesy for professional relationships.

3.6. Addressing PIA’s Challenges for Collaborating with LEAs

To address PIs’ difficulty collaborating with LEAs, the interview respondents put forward substantial suggestions, including: creating opportunities for formal mixed training or conferences; identifying expert PIs to be in contact with law enforcement officers specialized in human trafficking investigations in each county or state; LEAs signing contracts with expert PIs; having the state manage the licensing of PIs and allowing access to crime databases; PIs volunteering their time for investigations of suspect human trafficking cases; etc. Illustrating some of these points, K.R. suggested,:

An association of both PIs and law enforcement officers that come together under one header and one topic so that we can have that ability to communicate with law enforcement officers. They also then have the availability to reach out to those PIs in those areas. So, it really needs to come under one umbrella.

J.K. had a similar idea:

I would start locally and have a spokesperson. You know, more teaching and training about it and bringing the PIs together with law enforcement. We do group meetings more like every quarter, we always have a speaker or a topic. ‘Here’s what we can do, do you see a lot of this?’ and ‘Do you know how prominent this is in your area?’

K.R. explained that if LEAs would agree to participate in co-sponsored training, then this would first get everyone on the same page and give collaboration and networking abilities. Doing so helps develop comradery through face-to-face meetings. He explained that PIs in his county in Texas did meet the local sheriff informally and regularly and discussed issues around human trafficking. “But it will be more effective if we formalize discussions on a monthly or bi-monthly or twice a year basis, maybe three professionals in human trafficking to do a seminar, a webinar, or a meeting between all the interested parties,” he said. J.J. proposed that law enforcement should take the initiative by partnering with their state’s association of PIs to organize training and talks with PIs, because, as she said,

Some PIs don’t really know whom to call because they don’t have the skill. So, let’s give them the tools. If you have a family that comes in and they are asking and bringing this up, your antenna should go up, and you should immediately call law enforcement and pass that information along.

According to D.L., “Intelligence officers should work with us; those are the best law enforcement agents I’ve worked with. It’s not necessarily a detective or patrol [officer], but the intelligence officers; I have a great relationship with them.” R.H. described how PIAs could contract with PIs by allocating some funding for assistance by outside people for specific investigations. He said, “If they are looking at changing the police now, I believe they would include the private sector, mainly PIs, in these types of cases; it would increase their assets.” Then, they should invite licensed PIs to the team to collaborate. “I think that would go a long way in breaking down the barriers we have between the two entities,” B.W. said.

Finally, B.K. suggested developing a network of investigators in the state who are willing to carry out that type of volunteer work, and then they could present themselves to law enforcement and say,

Hey, we are a dozen PIs here in the state of Tennessee; we volunteer our time; this is the name of our group. I think power comes from numbers, and I’ve even thought of expanding that. Here in the southeast region, if we could have a network and expand that network of volunteer PIs into other states, that would be powerful.

According to some respondents, it can be very difficult for PIs to be given due respect for human trafficking investigations if they do not make efforts to have a relationship with others in the criminal justice system apart from law enforcement. S.R., whose investigation agency developed a strong connection with state attorneys and prosecutors, showed how doing so helped his agency to negotiate around obstacles of working with LEAs. As he explained:

You may be able to recover a victim and get them back to their family, but there is still a trafficker out there that must face justice and be arrested. If you don’t have a connection or a liaison with the law enforcement officers or the prosecutors, then you’ll never be able to get that person prosecuted.

He reported that his agency had a relationship with the district attorney in the state capital city, whose specific role was prosecuting human trafficking cases.

We’ll bring our cases directly to her, and then sometimes she’ll send us cases and say, ‘Hey, I can’t get metro PD to work this case because they don’t have the time. Can you go flush it out and let us know if it is trafficking or if it’s not trafficking?’ and we’ll do that with her. But having a relationship with prosecution or law enforcement is a must, concluded S.R.

Likewise, C.L., a veteran PI with over 50 years of experience, described how PIs could connect with major stakeholders by volunteering with any state attorney’s division on human trafficking:

They need to donate their time in the human trafficking division in the district attorney’s office. They will find civilians working in that office. The district attorney’s office is not like the policemen; it will cooperate much more with PIs than the policemen will.

4. Discussion

An observation about the demographic characteristics of the study sample is that most of the participants were former law enforcement officers with substantial work experience in vice units at several levels (i.e., federal, state, city, etc.). The length and wealth of professional law enforcement experience reported could be considered a key strength in enhancing their work, and more importantly, their collaboration with law enforcement agents still in service. Hounmenou and O’Grady [57] show that PIs have versatile skills and substantial experience in conducting human trafficking investigations, which make them key stakeholders and resourceful professionals—overlooked till now—for collaboration with LEAs to address human trafficking and recover victims.

4.1. Interagency Collaboration between PIAs and LEAs

The survey finding that most of the 39 survey participants (61%) believed that PIAs would collaborate with LEAs rarely, while 29% would do so sometimes, indicates that collaboration between PIAs and LEAs occurs at a very small scale and mostly informally. It also shows some distrust between these two sides of the investigation. This point was further reinforced by the finding that 10 of the 39 participants reported not having associated with LEAs for any human trafficking investigations they had conducted. Another finding further emphasizes these two findings highlighting challenges in the collaboration of PIAs with LEAs: the average rating close to 4 on a scale of 1–5 for the participants’ level of perception of difficulty for PIAs to work with LEAs.

Despite the perception that it is challenging to get LEAs to collaborate with PIAs on trafficking investigations, it is noteworthy that most of the 39 survey participants (32%) acknowledged that it was very important for PIAs to collaborate with LEAs for investigations of human trafficking. Yet, most of the participants also perceived that PIAs’ assistance to LEA-led investigations is relatively more important than LEAs’ assistance to PIA-led investigations. The findings that three out of every four PIAs (74%) were reported as having collaborated with LEAs on trafficking-related investigations and that seven out of every ten PIAs (70%) did so 1–5 times are important because these findings indicate that the expertise of PIAs for human trafficking work is acknowledged and solicited by some LEAs. However, the findings from the interviews discussed next not only corroborate most of the survey findings but also highlight substantial nuances and challenges in collaboration between PIAs and LEAs.

The interview findings that the agencies of 20 of the 28 respondents (71%) collaborated, to varying extents, with LEAs on trafficking-related investigations, and that some agencies collaborated with LEAs on all trafficking cases they investigated, indicate some visibility and recognition of PIA by LEAs in the fight against human trafficking. It was found that successful collaborations often depended on the state where the PIAs worked. For instance, PIs who previously had an excellent partnership with LEAs in New York later met many challenges for similar opportunities in a state such as Tennessee. The level of collaboration between PIAs and LEAs, and other public institutions in New York and other states such New Jersey, as reported in this study, indicates that the potential for PIAs to enhance human trafficking investigations is not overlooked in some areas of the criminal justice system. The interview respondents emphasized the importance of PIAs reaching out to LEAs for mutual support in the trafficking-related investigations they initiated. This indicates the availability of PIAs to assist and supplement law enforcement for improved investigation outcomes. Though they acknowledged the importance of both PIAs and LEAs collaborating on human trafficking, assessing whether LEAs would be open to compromise around sharing information and collaboration would be valuable.

However, collaboration with LEAs was found to be highly dependent on the size of the PI’s network and past law enforcement career. Participants who successfully partner with LEAs could be found mostly among PIs who were former law enforcement agents, and to some extent, among well-known veteran PIs with excellent track records and extensive connections. Contrary to PIs younger than 50, those in their 60s and 70s tend to have more success collaborating with LEAs because, as some of them explained, it takes time to create networks, and a past career in law enforcement appears to be a key factor in gaining the trust of LEAs.

Among the distinctive contributions PIAs could make to investigations initiated by LEAs, three deserve discussing: the ability to provide training to law enforcement, the ability to be an intermediary between law enforcement and victims’ families, and the ability to locate missing persons and conduct surveillance. First, veteran PIs reported and described their experience of training hundreds of LEAs. They could contribute to strengthening LEAs’ capacity because of the extensive professional experience of most of them in both law enforcement and the PI field. LEAs could use PIs as persons of resources by contracting with them to train their staff about advanced interview skills and interactions with trafficking victims. For example, research shows that LEAs sometimes hire specialized staff with IT backgrounds to help train and increase the educational requirements for their staff across the board [9]. First, similar contract initiatives could be developed to get PIs to work with LEAs. Second, considering the victim-protection approach they prioritize, PIs could be excellent intermediaries between families and LEAs on the one hand and between victims and LEAs on the other hand. Victims and families are likely to trust PIs more because of their victim-centered service approach. Research shows that law enforcement has difficulty developing trust with trafficking victims, which is necessary to gather information during investigations [10,14].

Third, considering their advanced skills in locating missing people and conducting surveillance, PIs could provide critical support for LEAs in tracing and recovering victims of trafficking. However, as stressed through the interview findings, PIAs must make efforts to inform LEAs about the investigations of trafficking they conduct to obtain technical support only LEAs can provide because LEAs have exclusive access to federal and state crime data. Most respondents agreed that LEAs should share investigation information with PIAs because they have access to many databases and resources that PIAs do not have access to. PIs acknowledge that LEAs’ intervention in any criminal investigation is crucial. Only LEAs have the legal powers to arrest crime perpetrators, even if sometimes PIs can make citizen’s arrests. LEAs have the power of the law and the authorization to use lethal force.

4.2. Obstacles to PIA–LEA Partnership

Collaboration between PIAs and LEAs does not often occur without obstacles. In many cases, LEAs tend to solicit investigation information from PIAs, but they cannot or will not reciprocate and help PIAs. Interestingly, it was found that when LEAs decide to share information with PIAs, they tend to provide misleading information. Due to issues of police culture, ego, distrust, and selfishness, law enforcement officers dislike working with PIs because they want to avoid advice from outsiders about how they should conduct investigations [27,38]. Law enforcement’s lack of familiarity with the private security sector’s policing roles [36,38] appears to contribute to their distrust of PIs. Young law enforcement officers often make mistakes in investigations, but it would be an outrage to take any advice from PIs about an investigation. Even within their corporation, LEAs do not regularly communicate and do not share intelligence data [7]. Thus, it should not be surprising that LEAs dislike collaborating with PIAs. A feeling of power entitlement and legitimacy among LEAs could partly explain why they tend to disregard what PIAs could potentially contribute to investigations [24,27].

Nevertheless, as the findings show, sometimes, it is against the law for LEAs to share information with anyone outside the law enforcement circle regarding any investigations. Some respondents pointed out that most jurisdictions in the U.S. restrict access to most law enforcement databases. Thus, beyond selfishness, distrust, and condescension reported about law enforcement in interaction with PIAs, a major barrier to information sharing by LEAs has a lot to do with laws that regulate information LEAs can share with private citizens.

4.3. Improving Partnerships for Investigations of Human Trafficking

The themes from the interviews provide important information about the ways law enforcement can value PIs’ input in efforts of prevention, protection, and prosecution of human trafficking. Law enforcement should give due regard to PIA’s capacity to investigate crimes such as human trafficking. Consideration should be given to PIAs’ capacity to complement LEAs in investigations of human trafficking. It is possible that cooperating with PIAs could be highly beneficial for some investigations for which LEAs lack time, human resources, and advanced skills in areas such as surveillance, interviews, locating missing persons, etc. The information in the present study provides a ground-breaking exploration of how PIAs’ skills could make them key partners, instead of adversaries, to LEAs.

As suggested by several participants, through opportunities for workshops and conferences, LEAs and PIAs can develop connections and share information about strategies to deal with human trafficking. LEAs could lead the way by establishing human trafficking investigations teams that would include PIs with expertise in this service area. Creating directories of specialists in trafficking investigations should be an initial, important step to get LEAs and PIAs to get to know and connect with each other. Such directories should be shared with associations of PIAs and LEAs at the city and state levels. LEAs should consider vetting and contracting with those proven to have expertise in human trafficking investigations. One strategy to help PIAs have access to some databases exclusively accessible to law enforcement would be by making entities such as the state police responsible for PI licensing, as it is currently carried out in New Jersey, according to a respondent. It would be good if other states followed this model of getting the state police to play a central role in licensing PIs and allowing them access to databases only accessible to LEAs. PIAs could circumvent the difficulty of collaborating with LEAs by reaching out to state attorneys and prosecutors and volunteering to build connections they could capitalize on later for assistance with human trafficking investigations. The participants concurred that PIAs should do their best to seek the assistance of LEAs regarding investigations of human trafficking whenever possible. However, it is important that information sharing be mutual.

5. Implications and Limitations

5.1. Implications for Practice

Law enforcement’s limitations in investigating human trafficking could be compensated by potential strengths that PIs could bring to such investigations, including time, surveillance, advanced interviewing, skip tracing, a victim-centered investigation approach, infiltrating criminal organizations, etc. Thus, it would be helpful if both sides of investigations—public and private—could develop initiatives to enhance efforts of addressing the fight against human trafficking and recovering victims. LEAs should view PIAs as potential complementary forces to improve efforts to investigate crimes in general and particularly human trafficking. They should look outside their box and reach out to PIs they feel could be key partners in their work in human trafficking investigations. LEAs should consider developing strategies for partnership with associations of PIAs in their jurisdictions or states, especially PIs with expertise on human trafficking whom LEAs could contract for investigations they have limited leads on. Information sharing should work both ways for more effective strategies for human trafficking investigations.

PIs with experience in human trafficking investigations should reach out and be willing to share information with LEAs about investigations of human trafficking they conduct or plan to do. As one of the interview participants said, “When human trafficking information comes to PIs, they need to be a conduit and pass that information on to law enforcement, or maybe they need to start the conversation, so maybe ask law enforcement to come in.” Yet, information sharing should be carried out with, first, a commitment of law enforcement not to treat rescued victims as criminals. Then, it should be carried out with the understanding that PIs obtain consent to do so from potential victims’ families that hire them. In addition to law enforcement, PIs should make themselves known to the various criminal justice stakeholders involved in human trafficking, such as state attorneys and prosecutors. In every state, human trafficking task forces should reach out to PIAs.

5.2. Implications for Policy

Policymakers at the state and federal levels should consider sponsoring studies that will be used to decide whether PIs could be legitimate partners to contribute to trafficking investigations. If so, efforts could be made to initiate combined training of PIAs and LEAs about how to collaborate on investigations of trafficking. Policymakers should adopt legislation to allow licensed PIs to access the same tools and national databases as LEAs for human trafficking investigations. States and foundations could create competitive funding opportunities for PIs to collaborate with LEAs and state attorneys on human trafficking investigations. Regulations should be established that call for the state police to facilitate licensing of PIs and establish conditions under which they can cooperate with LEAs on human trafficking investigations. Finally, it would be an important initiative for policymakers to create a state or national center to coordinate and fund collaborative investigations of human trafficking by LEAs and PIAs. This should be an independent investigation-focused entity, a national center funded through public and private funds, where law enforcement and PIs could meet to exchange knowledge and network.

5.3. Implications for Research

Full-scale research should be conducted to get policymakers, law enforcement, and the overall criminal justice system to understand how PIs can contribute to the fight against human trafficking. Thus, research subsequent to this study should focus on the following topics: first, law enforcement’s experiences of collaboration with PIs in criminal investigations, including human trafficking; second, comparing human trafficking investigation outcomes of LEAs collaborating with PIAs with LEAs without no similar partnerships; and third, an assessment of law enforcement’s perceptions of PIs as potential partners in the fight against human trafficking, and challenges to address for formal collaboration.

5.4. Study Limitations

The findings of this study cannot be generalized to any other populations of PIs anywhere because, first, the study involved purposive sampling; second, the sample, which is a subsample of another study, is small, especially for the survey component; third, only descriptive statistics were used, and univariate and bivariate analyses were performed on the survey data. Third, since the discussion of the findings from the interview data analysis is limited to only the 28 participants whose organizations conducted human trafficking investigations, no claims could be made about the accuracy of the self-reports made about their perceptions and experiences about collaborating with LEAs. Fourth, another limitation is the participation of two respondents from two other countries than the United States (i.e., Canada and Australia) in the study. While they could be considered outliers in the survey data, their substantial input in the interviews shows that PIs in developed countries share many similarities in their challenges in partnering with law enforcement. The participant from Canada conducted investigations and collaborated with law enforcement in the United States for over a decade. Fifth, the analysis and interpretations of the interview data might have been influenced by the researchers’ assumptions, values, and biases. Their interactions with the participants at the interview stage may be considered threats to credibility. However, using strategies such as member-checking and peer debriefing helped limit the potential threats to the credibility and confirmability of the findings in this study. Finally, the fact that this study explored only PIs’ perceptions and experiences of collaboration with LEAs is a key limitation because it provides one side story. It would be constructive to examine law enforcement’s perceptions and experiences of collaborating with PIAs in order to understand how such collaboration could be enhanced.