25 violation of this right, as would be the case of all measures necessary to prevent arbitrary killings by its own security forces, as well as to prevent and punish the deprivation of life as a consequence of 141 criminal acts carried out by individual third parties. 124. In line with the precedents set by the Inter-American Court, the Commission notes that although agents of state security forces may legitimately use lethal force in discharging their duties, that use must be exceptional and must be planned and proportionately constrained by the authorities; thus, “force or coercive means can only be used once all other methods of control have been exhausted and 142 have failed.” Similarly, Article 3 of the United Nations Code of Conduct for Law Enforcement Officials provides that: “Law enforcement officials may use force only when strictly necessary and to the extent 143 required for the performance of their duty”; and Principle No. 4 of the Basic Principles on the Use of 144 Force and Firearms by Law Enforcement Officials states that: “Law enforcement officials, in carrying out their duty, shall, as far as possible, apply non-violent means before resorting to the use of force and firearms. They may use force and firearms only if other means remain ineffective or without any promise of achieving the intended result.” 125. Consequently, the law must determine when state security agents may use lethal force; this must be restrictively construed, so that they are used only when absolutely necessary in relation to 145 the force or threat being countered. Clearly: State agents must distinguish between persons who, by their actions, constitute an imminent threat of death or serious injury and persons who do not present such a threat, and use force only against 146 the former. 126. The Commission notes that the use of excessive or disproportionate force by law 147 enforcement officials that results in the loss of life may amount to an arbitrary deprivation of life. For 141 I/A Court H. R., Case of Servellón García et al. v. Honduras, Merits, Reparations, and Costs, Judgment of September 21, 2006, Series C No. 152, para. 98; I/A Court H. R., Case of Montero Aranguren et al. (Detention Center of Catia) v. Venezuela, Preliminary Objection, Merits, Reparations, and Costs, Judgment of July 5, 2006, Series C No. 150, para. 64; I/A Court H. R., Case of Ximenes Lopes v. Brazil, Preliminary Objection, Judgment of November 30, 2005, Series C No. 139, para.125; and I/A Court H. R., Case of the Ituango Massacres v. Colombia, Preliminary Objection, Merits, Reparations, and Costs, Judgment of July 1, 2006, Series C No. 148, para. 131. 142 I/A Court H. R., Case of Zambrano Vélez et al. v. Ecuador, Merits, Reparations, and Costs, Judgment of July 4, 2007, Series C No. 166, para. 83; I/A Court H. R., Case of Montero Aranguren et al. (Detention Center of Catia) v. Venezuela, Preliminary Objection, Merits, Reparations, and Costs, Judgment of July 5, 2006, Series C No. 150, para. 67. 143 UN Doc. A/34/46 (1979), A.G. Res. 34/169. 144 Adopted by the Eighth United Nations Congress on the Prevention of Crime and the Treatment of Offenders, Havana, Cuba, August 27 to September 7, 1990. 145 I/A Court H. R., Case of Zambrano Vélez et al. v. Ecuador, Merits, Reparations, and Costs, Judgment of July 4, 2007, Series C No. 166, para. 84; I/A Court H. R., Case of Montero Aranguren et al. (Detention Center of Catia) v. Venezuela, Preliminary Objection, Merits, Reparations, and Costs, Judgment of July 5, 2006, Series C No. 150, para. 68. Similarly, see also: ECHR, Huohvanainen v. Finland, March 13, 2007, No. 57389/00, paras. 93-94; ECHR, Erdogan and Others v. Turkey, April 25, 2006, No. 19807/92, para. 67; ECHR, Kakoulli v. Turkey, November 22, 2005, No. 38595/97, paras. 107-108; ECHR, McCann and Others v. the United Kingdom, Judgment of September 27, 1995, Series A No. 324, paras. 148-150, 194; and Code of Conduct for Law Enforcement Officials, adopted by the United Nations General Assembly, Resolution 34/169, December 17, 1979, Article 3; Under Principle 11 of the Basic Principles on the Use of Force and Firearms by Law Enforcement Officials, adopted by the Eighth Congress on the Prevention of Crime and the Treatment of Offenders, held in Havana, Cuba, from August 27 to September 7, 1990, rules and regulations on the use of firearms by law enforcement officials should include clear guidelines that: (a) specify the circumstances under which law enforcement officials are authorized to carry firearms and prescribe the types of firearms and ammunition permitted; (b) ensure that firearms are used only in appropriate circumstances and in a manner likely to decrease the risk of unnecessary harm; (c) prohibit the use of those firearms and ammunition that cause unwarranted injury or present an unwarranted risk; (d) regulate the control, storage and issuing of firearms, including procedures for ensuring that law enforcement officials are accountable for the firearms and ammunition issued to them; (e) provide for warnings to be given, if appropriate, when firearms are to be discharged; (f) provide for a system of reporting whenever law enforcement officials use firearms in the performance of their duty. 146 I/A Court H. R., Case of Zambrano Vélez et al. v. Ecuador, Merits, Reparations, and Costs, Judgment of July 4, 2007, Series C No. 166, para. 85. Similarly: IACHR, Report on Terrorism and Human Rights, 2002.