The United States Constitution, treaties, federal statutes, executive orders, and court decisions establish and define the unique legal and political relationship that exists between the United States and Indian tribes. Federal laws vest the Department of Justice with primary jurisdiction over most felonies that occur on Indian lands. As such, the Federal Bureau of Investigation and the United States Attorneys' Offices are the primary federal law enforcement agencies responsible for investigating and prosecuting felony crimes that occur in Indian country.

United States Attorneys' Offices
The vast majority of criminal prosecutions for felony crimes committed within Indian country are handled by United States Attorneys' Offices. The designated Tribal Liaison within United States Attorneys' Offices may be contacted regarding issues that arise in Indian Country. The United States Attorneys' Offices have identified five basic priorities on which to focus in Indian country: (1) Homeland security, (2) Violent crimes, (3) Indian gaming, (4) White collar crime, and (5) Jurisdictional issues.

Federal Bureau of Investigation
Within the FBI's Criminal Investigative Division, the Indian Country Unit (ICU) is responsible for developing and implementing strategies, programs, and policies to address identified crime problems in Indian Country for which the FBI has responsibility.The ICU's responsibilities include: management of manpower resources; oversight of budgetary and resource issues; procurement of services and equipment; and the provision of assistance and training to Special Agents of the FBI, Bureau of Indian Affairs (BIA), and tribal officers to ensure that criminal investigations are performed in an effective, professional manner.