In October 2011, the Department of Justice Office of the Inspector General (OIG) initiated an audit of the United States Marshal Service's (USMS) management of the Witness Security (WITSEC) Program. In May 2013, the Department of Justice (Department) Office of the Inspector General (OIG) issued a report examining the Department's handling of known or suspected terrorists in the Federal Witness Security (WITSEC) Program. During that review, we identified sex offenders as another group of high-risk WITSEC Program participants (Program participants). Therefore, we conducted this audit to evaluate the Department's: (1) admission and vetting of sex offenders into the WITSEC Program; (2) handling, tracking, and monitoring of sex offenders who were Program participants; and (3) procedures for notifying states, local municipalities, and other law enforcement agencies regarding the relocation of sex offenders.