DOD Directive 5210.56: Arming And The Use Of Force

This issuance:
• Establishes policy and standards and assigns responsibilities for arming, carrying of firearms, and the use of force by DoD personnel performing security and protection, law and order, investigative, or counterintelligence duties; and for personal protection when related to the performance of official duties.
• Establishes policy and standards and assigns responsibilities for contractor personnel required to carry a firearm in accordance with applicable DoD contracts.
• Implements Section 1585 of Title 10, United States Code (U.S.C.), which authorizes civilian officers and employees of the DoD to carry firearms or other appropriate weapons while assigned investigative duties or such other duties as prescribed by the Secretary of Defense.
• Provides requirements, authorizations, and restrictions on carrying firearms and the use of force to protect DoD installations, property, and personnel, and to enforce law and order in accordance with DoD Instruction (DoDI) 5200.08 and DoD 5200.08-R.
• Implements Section 2672 of Title 10, U.S.C., Section 926A of Title 18, U.S.C., and Section 526 of Public Law 114-92 (“the National Defense Authorization Act for Fiscal Year 2016”), and authorizes DoD Components to arm DoD personnel qualified under Sections 926B and 926C of Title 18, U.S.C., when related to the performance of official duties.
• Provides guidance for permitting the carrying of privately owned firearms on DoD property by DoD personnel for personal protection purposes that are not associated with the performance of official duties.

The full directive can be found at the following location:
http://www.ncosupport.com/files/dod-directive-arms2016.pdf