During the Troubles in Northern Ireland, British security forces were accused by some of operating a "shoot-to-kill" policy, under which suspected paramilitary members were killed without an attempt being made to arrest them. This alleged policy was claimed to be most frequently directed against suspected members of Irish republican paramilitary organisations, such as the Provisional Irish Republican Army (IRA), Official Irish Republican Army (OIRA) and Irish National Liberation Army (INLA). According to a 1985 inquiry by a team of international lawyers titled Shoot to Kill?, undercover security force units were "trained to shoot to kill even where killing is not legally justifiable and where alternative tactics could and should be used." The British government, including the Northern Ireland Office, consistently denied that there was ever a "shoot-to-kill" policy, stating that "like everyone else, the security forces must obey the law and are answerable to the courts for their actions."
Notable incidents where a "shoot-to-kill" policy was alleged to have been used include the Loughgall ambush, ambush at Drumnakilly, Coagh ambush, Clonoe ambush and Operation Flavius. These incidents were all operations carried out by the security forces against the IRA and INLA, and resulted in 21 Irish republican paramilitaries being killed. Other notable incidents involving civilian deaths include the 7 August 1974 killing of an unarmed Catholic farmer (Patrick McElhone, aged 24) who was taken from his home outside of Pomeroy, County Tyrone and shot dead by a British Army patrol, found years later by a coroner to be "unjustified"; the death of Fergal Caraher, who was fatally shot by a Royal Marine at a checkpoint; and the killings of Karen Reilly and Martin Peake, who allegedly drove through a British Army checkpoint at high speed, with one soldier, Lee Clegg, subsequently being tried for the shootings. The killing of Ulster Volunteer Force (UVF) member Brian Robinson by undercover British soldiers is notable for being the most prominent of the very few alleged "shoot-to-kill" incidents where the victim was an Ulster loyalist.
On 24 May 1984, Deputy Chief Constable John Stalker of the Greater Manchester Police opened an inquiry into allegations that a specially trained undercover RUC team known as the "Headquarters Mobile Support Unit" had carried out a "shoot-to-kill" policy in three distinct cases:
The shootings were initially investigated by other members of the RUC, and the Director of Public Prosecutions for Northern Ireland decided to bring prosecutions. At the first trial, relating to the shootings of the two INLA men, Constable John Robinson admitted to having been instructed to lie in his statements, and that other witnesses had similarly altered their stories to provide justification for opening fire on Grew and Carroll. When Robinson was found not guilty, the resulting public outcry caused RUC Chief Constable John Hermon to ask John Stalker to investigate the killings.
On 5 June 1986, just before Stalker was to make his final report, he was removed from his position in charge of the inquiry. On 30 June, he was suspended from duty over allegations of association with criminals. On 22 August, he was cleared of the allegations and returned to duty, although he was not reinstated as head of the inquiry. The inquiry was taken over by Colin Sampson of the West Yorkshire Police. Its findings were never made public.
In the book Stalker, published by Stalker in 1988, the following descriptions of his investigation into the three shooting incidents appeared, concerning the McKerr, Toman and Burns shooting:
Concerning the three incidents as a whole, Stalker wrote:
According to The Times of 9 February 1988, Stalker stated that although he never found written evidence of a shoot-to-kill policy, there was a "clear understanding" that officers were expected to enforce it.
In 1990 the RUC issued a response to Stalker's book, saying that the book contained many inaccuracies and distortions and gave a misleading impression. In particular it stated, in contradiction to Stalker's assertions, that:
Criticisms were also made that Stalker had gone outside his remit to reinvestigate the shooting incidents as well as a terrorist incident on 27 October 1982 in which three police officers had been killed and that his report, when submitted, lacked the clarity and precision normally associated with criminal investigations.
The government also submitted that, on 23 June 1992, John Thorburn (the number two on Stalker's inquiry team), when withdrawing a libel action against the RUC Chief Constable, had made a statement in which he took the opportunity to submit publicly that he was satisfied that the RUC had not pursued a shoot-to-kill policy in 1982 and that the RUC Chief Constable had not condoned or authorised any deliberate or reckless killings by his officers. Other members of the Stalker/Sampson inquiry team also stated in June 1990 that "the Greater Manchester officers wish to stress that the Stalker/Sampson Enquiry found no evidence of a 'Shoot to Kill policy'".
Some of the victims' families were awarded reimbursement of legal expenses from the Ministry of Defence following cases brought to the European Court of Human Rights against the British government. The European judges considered four cases between 1982 and 1992 in which 14 people were killed. They involved the deaths of 12 IRA members and two civilians (one a Sinn Féin member) by the SAS, the RUC and the loyalist Ulster Defence Association, allegedly acting in collusion with the RUC.
In the judgement, the court ruled that eight armed IRA men shot dead by soldiers of an SAS unit at Loughgall, County Armagh, in 1987, and two IRA men killed by RUC officers, had their human rights violated. It said this had arisen because of the failure of the state authorities to conduct a proper investigation into the circumstances of the deaths, though the court did not rule that the use of lethal force itself was unlawful. A similar finding was brought in the case of Sinn Féin member Patrick Shanaghan, who was killed by loyalist paramilitaries. The findings were brought under Article 2 of the European Convention on Human Rights.
A number of television programmes were produced about or in reaction to specific incidents in particular or the shoot-to-kill issue in general: