Courts-martial of the United States are trials conducted by the U.S. military or by state militaries. Most commonly, courts-martial are convened to try members of the U.S. military for violations of the Uniform Code of Military Justice (UCMJ). They can also be convened for other purposes, including military tribunals and the enforcement of martial law in an occupied territory. Federal courts-martial are governed by the rules of procedure and evidence laid out in the Manual for Courts-Martial, which contains the Rules for Courts-Martial (RCM), Military Rules of Evidence, and other guidance. State courts-martial are governed according to the laws of the state concerned. The American Bar Association has issued a Model State Code of Military Justice, which has influenced the relevant laws and procedures in some states.
Courts-martial are adversarial proceedings, as are all United States criminal courts. That is, lawyers representing the government and the accused present the facts, legal aspects, and arguments most favorable to each side; a military judge determines questions of law, and the members of the panel (the military equivalent of a jury) (or military judge in a judge-alone case) determine questions of fact.
State National Guards (air and army), can convene summary and special courts martial for state-level, peacetime military offenses committed by non-federalized Guard Airmen and Soldiers, in the same manner as federal courts martial proceed. The authority for State National Guards to convene courts martial is under Title 32 of the US Code. States that have militaries (State Guards) outside the federally regulated National Guard convene courts-martial by authority of state laws.