National Security Act of 1947

The National Security Act of 1947, as amended, provides that the Director of National Intelligence (DNI) is responsible for providing timely and objective national intelligence “based upon all sources available to the intelligence community and other appropriate entities.” The Secretary of Defense has significant authorities and responsibilities related to the collection of national intelligence.

The National Security Act expressly provides for the use of intelligence to assist law enforcement officials abroad:


 * [E]lements of the intelligence community may, upon the request of a United States law enforcement agency, collect information outside the United States about individuals who are not United States persons. Such elements may collect such information notwithstanding that the law enforcement agency intends to use the information collected for purposes of a law enforcement investigation or counterintelligence investigation.

DOD intelligence agencies are subject to certain limitations when providing such assistance. 50 U.S.C. §403-5a(b) provides that such assistance “may not include the direct participation of a member of the Army, Navy, Air Force, or Marine Corps in an arrest or similar activity” and may not be provided “if the provision of such assistance will adversely affect the military preparedness of the United States.”  The Secretary of Defense is required to establish regulations governing the provision of assistance to law enforcement agencies by DOD intelligence elements.

The National Security Act neither authorizes nor prohibits the use of intelligence for law enforcement purposes within the United States, but other statutes apply, including the Posse Comitatus Act.