Improper use of force by non-state actors is not usually called extrajudicial punishment, such actions are more properly called assassination, guerrilla warfare, murder (in the case of attacks on unarmed civilians) or vigilantism instead.
Another possibility is for overtly uniformed security forces to punish a victim, but under circumstances that make it appear as self-defense, such as by planting recently-fired weapons near the body, or fabricating evidence suggesting suicide. In such cases, it can be difficult to prove that the perpetrators acted wrongly. Because of the dangers inherent in armed confrontation, even police or soldiers who might strongly prefer to take an enemy alive may still kill to protect themselves or civilians, and potentially cross the line into extrajudicial murder. Only in the most obvious cases, such as the Operation Flavius triple killing or the shooting of Jean Charles de Menezes will the authorities admit that "kill or capture" was replaced with "shoot on sight".
Extrajudicial punishment is often a feature of politically repressive regimes, but even self-proclaimed or internationally recognized democracies have been known to use extrajudicial punishment under certain circumstances.
Extrajudicial punishment may be planned and carried out by a particular branch of a state, without informing other branches, or even without having been ordered to commit such acts. Other branches sometimes tacitly approve of the punishment after the fact. They can also genuinely disagree with it, depending on the circumstances, especially when complex intragovernment or internal policy struggles also exist within a state's policymaking apparatus.
In times of war, natural disaster, societal collapse, or in the absence of an established system of criminal justice, there may be increased incidences of extrajudicial punishment. In such circumstances, police or military personnel may be unofficially authorised to punish severely individuals involved in rioting, looting or other violent acts, especially if caught in flagrante delicto. This position is sometimes itself corrupted, resulting in the death of merely inconvenient persons, that is, relative innocents who are just in the wrong place at the wrong time.
A "disappearance" occurs where someone who is believed to have been targeted for extrajudicial execution does not reappear alive. Their ultimate fate is thereafter unknown or never fully confirmed.
During the apartheid years South Africa's security forces were also accused of using extra-judicial means to deal with their political opponents. After his release, Nelson Mandela would refer to these acts as proof of a Third Force. This was denied vehemently by the administration of F.W. de Klerk. Later the South African Truth and Reconciliation Commission, led by Archbishop Desmond Tutu would find that both military and police agencies such as the Civil Cooperation Bureau and C10 based at Vlakplaas were guilty of gross human rights violations. This led the International Criminal Court to declare apartheid a crime against humanity.
Torture remains a frequent method of interrogation and repression in totalitarian regimes, terrorist organizations, and organized crime. In authoritarian regimes, torture is often used to extract false confessions from political dissenters, so that they admit to being spies or conspirators, preferably manipulated by a foreign country. Most notably, such a dynamic of forced confessions marked the justice system of the Soviet Union during the reign of Stalin (thoroughly described in Aleksandr Solzhenitsyn's Gulag Archipelago).
The subject of extrajudicial punishment was examined in the stage play and subsequent film A Few Good Men. In this film, two marines are put on trial for the death of another marine due to their administering of a Code Red (a military colloquial speech term for extrajudicial punishment) on him.
There are currently a wide variety of databases available which attempt to measure, in a rigorous fashion exactly what governments do against those within their territorial jurisdiction. The list below was created and maintained by Prof. Christian Davenport at the University of Maryland. These efforts vary with regard to the particular form of human rights violation they are concerned with, the source employed for the data collection as well as the spatial and temporal domain of interest.