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Gaps in Reporting Human Trafficking Incidents Result in Significant Undercounting

Deficient data on the incidence of human trafficking offenses reflect pervasive issues with incident identification and reporting, a study combining stakeholder interviews and data analysis shows.
Date Published
August 4, 2020

Crime statistics on human trafficking are only as solid as the crime data informing them. Recent NIJ-supported research reveals that labor and sex trafficking data appearing in the FBI’s national Uniform Crime Reporting (UCR) Program may significantly understate the extent of human trafficking crimes in the United States.

Before this, there had been no research on the validity of UCR data on human trafficking, the researchers noted. An objective of the study was to advance understanding of how accurately reporting of human trafficking crimes reflects the true incidence of crime in a community.

Researchers discovered a widespread inability of law enforcement officers to identify local trafficking offenses, coupled with inadequate reporting of those offenses that were identified. That insight was the product of extensive record reviews and structured interviews with law enforcement and social service providers. Extrapolating their findings from three study sites to a national scale, the research team led by Amy Farrell, a Northeastern University criminologist, concluded that “the UCR Program undercounts both human trafficking offenses that exist in local communities and human trafficking offenses that are identified by local law enforcement.”

The crux of the problem is that, in order for us to make accurate estimations of human trafficking from the collected data, law enforcement investigators need to be able to identify the victims. The study found that inadequate victim identification was a problem not only for law enforcement but also for victim service providers. As a result, the data collections available for study are limited and tend to underrepresent the victim populations.

Trafficking Incidence Far Exceeds Trafficking Reports

In two of the three study sites [1] — jurisdictions with populations of 2.3 million and 600,000, respectively — researchers concluded that human trafficking incidents identified in law enforcement and social service agency records likely represented only a fraction of the actual incidence. The study found that the official trafficking numbers in one jurisdiction represented as little as 14% and at most 18% of the potential total trafficking victims.[2] Looking at law enforcement’s human trafficking records alone, underreporting in those two jurisdictions was even more acute, with no more than 6% of potential human trafficking victims captured in police records in both jurisdictions, the research report noted.

In 2008, a federal statute for protecting trafficking victims authorized the FBI to start collecting offense and arrest data on trafficking as part of the UCR Program. In 2013, the UCR Program started collecting information in its Summary Reporting System and the National Incident-Based Reporting System on human trafficking in commercial sex acts and human trafficking in involuntary servitude (i.e., sex trafficking and labor trafficking).

The deficiency of UCR data on trafficking crimes is attributable to three primary factors, the report said:

  1. The relative recency of the incorporation of trafficking data in UCR, with some jurisdictions moving more quickly than others to contribute their data to that central crime data source.
  2. Deficient identification of potential human trafficking incidents by local law enforcement.
  3. Incomplete reporting of identified offenses at the local and state agency levels.

Many Officers Unable To Identify Human Trafficking or Not Inclined To Report It as Such

Interviews with law enforcement personnel found three main challenges to identification of trafficking offenses by law enforcement, the report stated:

  1. Lack of training of law enforcement personnel.
  2. The fact that identification of human trafficking victims is often pushed to later stages of criminal justice proceedings.
  3. The fact that the nature of human trafficking crimes often complicates identification. A common problem for officers is difficulty separating human trafficking from other offenses, such as prostitution, the researchers reported. Where human trafficking offenses were identified, they were often recorded as other offenses on incident reports, in some instances because offense codes for human trafficking do not exist in records systems or incident reports.

Specialized investigators were better equipped to identify trafficking offenses, according to the study, but those investigators often hesitated to record a trafficking offense as such. In some instances, specialized investigators said they only coded incidents as trafficking offenses if an individual was arrested and charged with a trafficking offense by a prosecutor. State law enforcement personnel interviewed in one jurisdiction said officers hesitate to report incidents as human trafficking when they involve juvenile victims, because of special victim information reporting requirements. In classifying offenses, officers often defer to the prosecutor. The researchers found that, across studied jurisdictions, officers lacked the ability to identify labor trafficking.

Part of the complexity of human trafficking crimes is that, by definition, they must be the result of force, fraud, or coercion. For a case to be prosecuted, it is usually vital that victims be able to provide information on commercial labor or sex operations that can be corroborated. But researcher interviews of victims reflected that they are often reluctant to share information on their traffickers. In some instances, victims were not initially aware that their circumstances constituted human trafficking.

Beyond inadequate identification of human trafficking offenses, the UCR data are depressed by gaps in local crime reporting to state crime reporting programs and the failure of some state programs to maintain human trafficking crime classifications.

Recommendations From the Researchers

The researchers’ recommendations for law enforcement agencies included, among other actions:

  • Continued training of officers on how to spot a trafficking case, how to record it, and how to refer it to special investigators.
  • Establishment of nontraditional partnerships between law enforcement, labor regulators, inspection services, youth service providers, and immigration advocates to address labor trafficking.
  • Cooperation between law enforcement and prosecutors to develop other kinds of evidence, besides victim testimony, to prosecute trafficking cases.

Recommendations for non-law enforcement agencies included:

  • Training and supervision of agency staff on identifying trafficking victims; development and adoption of standardized tools to identify trafficking incidents.
  • Creation of a uniform trafficking database to be used across agencies.

The team also made recommendations for improving population estimates of trafficking victims. In this field of inquiry, estimation methods are still being tested, and data collection systems vary widely.


The challenges that human trafficking crimes pose for law enforcement and social service agencies are compounded by both the widespread inability of authorities to identify trafficking cases and the broadly inadequate reporting of vital human trafficking data. The Northeastern University research team urged that accurate identification of victims and accurate reporting are critical to addressing labor and sex trafficking and to supporting trafficking victims, their service providers, and law enforcement.

The inclusion of trafficking crimes in UCR was an important step toward enabling law enforcement and social service agencies to fully grasp the scope of the problem and provide a measured response. But research has found that current UCR trafficking numbers probably significantly underreport actual incidence, capturing only a fraction of trafficking crimes.

A key reason for the reporting gap is a pervasive and critical lack of trafficking identification in jurisdictions across the nation. For a variety of reasons, many human trafficking cases investigated by law enforcement are simply not identified as such, even in agencies with specially trained staff. Social service providers have also frequently failed to identify trafficking incidents, and they often underreported the human trafficking incidents known to their agencies.

Better training of officers, and of the service providers who address both sex and labor trafficking, will improve enforcement against traffickers and ensure needed support of victims, the report said. Better training of crime data development staff will produce a more complete picture of the human trafficking problem.

About This Article

The research described in this article was funded by NIJ grant 2015-VF-GX-0105, awarded to Northeastern University. This article is based on the grantee final report “Capturing Human Trafficking Victimization Through Crime Reporting” (pdf, 41 pages) (2019), by Amy Farrell (PI), Meredith Dank, Matthew Kafafian, Sarah Lockwood, Rebecca Pfeffer, Andrea Hughes, and Kyle Vincent.

Date Published: August 4, 2020