Summary execution of Viet Cong agent. photo: Eddie Adams

A summary execution is a type of extrajudicial punishment in which a person suspected of subversive or other criminal activity is killed, often at the time and place of their being discovered, and hence usually without any meaningful inquiry or investigation. Summary executions typically occur in a theatre of war, or in a protracted riot or other context of profound instability where a functioning criminal justice system is unavailable. To define further, they also typically occur outside; bringing the accused to an office or lockup, or before the finders' superior, is generally a prelude to an inquest or trial.

Summary executions are often carried out using expedient means such as a firearm, though hanging, stabbing, stoning, and decapitation have also been used. Poisoning, electrocution, and other tortures require controlled conditions and would be impractical. They are often a tactic of early resort employed by groups involved in guerrilla warfare.

See also: lynching, piracy