8. These principles will apply, for example, in the context of a riot or insurrection. Throwing stones at fully armed and protected officers is unlikely to justify resort to lethal force. Appropriate riot control procedures and equipment must be used.202 In relation to prison uprisings, the proportionality of the use of fatal force will be strictly applied. Therefore, when lethal force was used to contain a prison uprising involving serious and violent offenders resulting in extensive loss of life, the manner of the use of lethal force was found to be excessive and disproportionate and consequently a violation of the right to life.203 9. There should be an appropriate regulation of the use of firearms which is in accordance with international standards including the United Nations Principles on the Use of Force and Firearms by Law Enforcement Officials. 204 10. A targeted killing, namely, according to the Special Rapporteur on Extrajudicial Arbitrary and Summary Executions, one that is ‘intentional, premeditated and deliberate killing by law enforcement officials’ cannot be legal as it has its sole objective to kill.205 Similarly, ‘shoot to kill’ policies will also violate international human rights law.206 Deaths in custody 11. Where an individual dies in custody there is a presumption of State responsibility.207 The burden of proof falls on the State to identify the cause of death.208 Extra-judicial summary or arbitrary executions 12. States are required to conduct thorough, prompt and impartial investigations into any suspected cases of extrajudicial, summary or arbitrary execution.209 13. States are also required to bring the perpetrators of such executions to justice and provide compensation to victims’ families.210 14. In its concluding observations, the Human Rights Committee has expressed concern with respect to the alleged use of so-called ‘targeted killings’ of suspected terrorists. The Committee has emphasised that State parties, 202 Gulec v Turkey, European Court, 27 July 1998. Inter-American Court, Neira Alegria v Peru, judgment 19 Sep 1996. 204 See e.g. Human Rights Committee, Concluding Observations: Portugal, CCPR/CO/78/PRT (2003), para. 9. 205 Report on targeted killings, A/HRC/14/24/Add.6, para 33. 206 Ibid. See also A/61/311; E/CN.4/2006/53, paras 44-54. 207 A/HRC/13/24, para 49. 208 Special Rapporteur on extrajudicial executions, A/61/311, paras 49-54. Varnava and others v Turkey, 18 September 2009. 209 Principles on the Effective Prevention and Investigation of Extralegal, Arbitrary and Summary Executions, ECOSOC Resolution 1989/65, Annex. GA Resolution 67/168, 15 March 2013, para 3. 210 Ibid. 203 53