Death squads are often, but not exclusively, associated with the violent political repression of dictatorships, totalitarian states and similar regimes. They typically have the tacit or express support of the state, as a whole or in part (see state terrorism). Death squads may comprise a secret police force, paramilitary group or official government units with members drawn from the military or the police. They may also be organized as vigilante groups.

Death squads may be distinguished from terrorist groups in that their violent actions are used to maintain the power of a local or national elite, rather than intending to disrupt their existing authority per se. Foreign powers may aid states where death squads are active, usually without the international criticism that would be involved when supporting states that support terrorism. Some death squads, including those with links with corrupt elites, have been classified as terrorist organizations.

Death squads can go out on patrol willing to kill and looking for trouble or seeking to commit premeditated attacks against political opponents, alleged rebel sympathizers and any other people deemed "dangerous" or simply "undesirable" (e.g.. such as homeless and squatters) by authorities or local interest groups. They may also act to remove portions of the civilian populations whose existence is perceived as not serving the purposes of the ruling elite. Death squads have been used to kill whole classes of people who do not hold a specific ideology, religion or race, in opposition to that held by a real or perceived majority, one not considered as "acceptable."