JP 3-28, page 60

Chapter III III-4 JP 3-14 (5) Using force or physical violence, brandishing a weapon, discharging or using a weapon, or threatening to discharge or use a weapon except in self-defense; in defense of other DOD persons in the vicinity; or in defense of non-DOD persons, including civilian law enforcement personnel, in the vicinity when directly related to an assigned activity or mission. 4. Other Permissible Types of Military Support to Law Enforcement Agencies a. Training (1) DODI 3025.21, Defense Support of Civilian Law Enforcement Agencies, allows the Military Departments and DOD agencies to provide training that is not “large scale or elaborate” and does not permit a direct or regular involvement of military personnel in activities that are traditionally civilian law enforcement operations. (2) Training assistance is limited to situations where the use of non-DOD personnel would be impractical because of time or cost. (3) Training assistance cannot involve military personnel in a direct role in a law enforcement operation unless otherwise authorized by law, and this assistance will only be rendered at locations where law enforcement confrontations are unlikely. b. Expert Advice. IAW Title 10, USC, Section 273, and DODI 3025.21, Defense Support of Civilian Law Enforcement Agencies, SecDef has directed that Military Departments and DOD agencies may provide expert advice as long as military personnel are not directly involved in activities that are fundamentally civilian law enforcement operations. c. Equipment. LEA requests for loans of equipment, maintenance, facilities, or personnel shall be made and approved IAW DOD policy and instructions for requesting DSCA and require SecDef approval. d. Use of DOD Personnel to Operate or Maintain Equipment. DOD personnel made available under Title 10, USC, Section 274(b), may operate equipment for the following purposes: (1) Detection, monitoring, and communication of the movement of air and sea traffic. (2) Detection, monitoring, and communication of the movement of surface traffic outside of the geographic boundary of the US and within the US not to exceed 25 miles of the boundary if the initial detection occurred outside of the boundary. (3) Aerial reconnaissance. (4) Interception of vessels or aircraft detected outside the land area of the US for the purposes of communicating with such vessels and aircraft and directing such vessels and aircraft to a location designated by appropriate civilian officials.