D.C. Code § 49-505

No action or proceeding shall be prosecuted or maintained against a member of a military court, or officer or person acting under its authority or reviewing its proceedings on account of the approval or imposition or execution of any sentence, or the imposition or collection of fine or penalty, or the execution of any warrant, writ, execution, process, or mandate of the military court, nor shall any officer or enlisted man be liable to civil or criminal prosecution for any act done while in the discharge of his military duty.