The purpose of the study was to explore how local law enforcement were responding to the crime of human trafficking after the passage of the Trafficking Victims Protection Act (TVPA) in 2000. The first phase of the study (Part 1, Law Enforcement Interview Quantitative Data) involved conducting telephone surveys with 121 federal, state, and local law enforcement officials in key cities across the country between August and November of 2005. Different versions of the telephone survey were created for the key categories of law enforcement targeted by this study (state/local investigators, police offices, victim witness coordinators, and federal agents). The telephone surveys were supplemented with interviews from law enforcement supervisors/managers, representatives from the Federal Bureau of Investigation's (FBI) Human Trafficking/Smuggling Office, the United States Attorney's Office, the Trafficking in Persons Office, and the Department of Justice's Civil Rights Division. Respondents were asked about their history of working human trafficking cases, knowledge of human trafficking, and familiarity with the TVPA. Other variables include the type of trafficking victims encountered, how human trafficking cases were identified, and the law enforcement agency's capability to address the issue of trafficking. The respondents were also asked about the challenges and barriers to investigating human trafficking cases and to providing services to the victims. In the second phase of the study (Part 2, Case File Review Qualitative Data) researchers collected comprehensive case information from sources such as case reports, sanitized court reports, legal newspapers, magazines, and newsletters, as well as law review articles. This case review examined nine prosecuted cases of human trafficking since the passage of the TVPA. The research team conducted an assessment of each case focusing on four core components: identifying the facts, defining the problem, identifying the rule to the facts (e.g., in light of the rule, how law enforcement approached the situation), and conclusion.