More than a decade after the passage of the United States' federal law against human trafficking, there continues to be a lack of systematic information about the characteristics of labor trafficking victimization and how labor trafficking cases are investigated by law enforcement. This study sought answers to: 1) What is the nature of the labor trafficking victimization experience in the U.S.?; 2) How are domestic and international labor trafficking syndicates operating in the U.S. organized? Who are the traffickers, and what is their connection to other illicit networks that help facilitate labor trafficking operations?; and 3) What are the challenges of law enforcement investigating labor trafficking cases identified by victim service providers? Why are so few identified cases investigated and prosecuted? The study's findings detail the nature of the labor trafficking victimization experience, who are the traffickers and how they operate, and challenges to investigation and prosecution. Finding included: All the victims in this study sample were immigrants working in the U.S. with most having entered on a temporary visa; some on diplomatic, business or tourist visas; others without legal authorization most commonly trafficked for agriculture and domestic work. All experienced at least some the following: elements of force, fraud and coercion necessary to substantiate labor trafficking, including document fraud; extortion; sexual abuse and rape; discrimination; psychological manipulation and coercion; torture; attempted murder; and violence and/or threats against themselves and their family members. And, that labor trafficking victims faced high rates of civil labor exploitation, including being paid less than minimum wage or less than promised; wage theft; and illegal deductions. A large number of policy and practice recommendations are provided to improve identification and response to labor trafficking and guide future research on labor trafficking victimization.