To support Iraqi efforts to prosecute members of the former Iraqi regime and in accordance with NSPD 37, the Justice Department established the Office of Regime Crimes Liaison (RCLO). Since 2004, RCLO has provided support and assistance to the Iraqi High Tribunal (IHT), which has jurisdiction to investigate charges of genocide, crimes against humanity, war crimes and violations of certain Iraqi laws committed between July 17, 1968 and May 1, 2003. The IHT has completed the Dujayl and Anfal cases, is currently conducting the 1991 Intifada trial, and has numerous investigations underway against former Iraqi officials.

During the trial of former dictator Saddam Hussein in 2005-2006, RCLO had approximately 140 personnel who served a variety of advisory, security, investigative and support functions, including: investigative agents from the FBI, DEA, ATF, and USMS; prosecutors; military officers; and foreign nationals. RCLO is transitioning into a smaller office that serves a more supportive role that will continue to advise the IHT until the court has completed its caseload. This reduced office will consist of four personnel.

At various times, RCLO also utilized the expertise of personnel from the Army Corps of Engineers and specialized contractors in the field. These include anthropologists, archaeologists, pathologists, and other forensic scientists have worked on the exhumations of mass graves and the preservation of evidence, as well as investigative consultants and international humanitarian law experts.