FBI - The FBI is the principal investigative arm of the United States Department of Justice. It has the authority and responsibility to investigate specific crimes assigned to it. The FBI also is authorized to provide other law enforcement agencies with cooperative services, such as fingerprint identification, laboratory examinations, and police training.
USDOJ - The Department of Justice is headed by the Attorney General of the United States. It employs about 120,000 persons including attorneys, investigators, border patrol agents, deputy marshals, correctional officers, and others. It is comprised of 38 separate component organizations. These include the U. S. Attorneys, the Federal Bureau of Investigation, the Drug Enforcement Administration, the Immigration and Naturalization Service, the Bureau of Prisons, the U. S. Marshals Service, and the Office of Justice Programs, among others.
CBP - The United States Customs Service is the primary enforcement agency protecting the Nation’s borders. It is the only border agency with an extensive air, land, and marine interdiction force and with an investigative component supported by its own intelligence branch.
ATF - The Bureau of Alcohol, Tobacco and Firearms (ATF) is a law enforcement organization within the United States Department of the Treasury with unique responsibilities dedicated to reducing violent crime, collecting revenue, and protecting the public.