26 guaranteed75. Such general obligation is particularly important in cases involving the lethal use of force. Upon learning that firearms have been used by members of its security forces and that such use had lethal consequences, the State has the obligation to initiate, ex officio and without delay, a serious, independent, impartial and effective investigation76 (infra paras. 119-124). This obligation is a fundamental and determining element of the protection of the right to life which is affected in such situations. 89. The European Court of Human Rights held that investigations on the excessive use of force must be open to public scrutiny, in order to assert the responsibility of state officials both in theory and in practice77. Moreover, the said Court held that the evaluation of the use of force involving the use of arms must take into consideration all the surrounding circumstances and the context in which the facts occurred, including such matters as the planning and control of the actions under examination78. 90. In short, any deficiency or fault in the investigation affecting the ability to effectively determine the cause of death or to identify the actual perpetrators or masterminds of the crime involve a failure to comply with the obligation to guarantee the right to life79. As such, the United Nations Special Rapporteur on Extrajudicial, Summary or Arbitrary Executions pointed out that: Human rights standards on the use of force derive from the understanding that the irreversibility of death justifies stringent safeguards for the right to life, especially in relation to due process. A judicial procedure, respectful of due process and arriving at a final judgment, is generally the sine qua non without which a decision by the State and its agents to kill someone will constitute an “arbitrary deprivation of life” and, thus, violate the right to life.80 * * * 75 Cf. Case of the Pueblo Bello Massacre, supra note 61, para. 142. See also Case of La Cantuta, supra note 7, para 110; Case of Vargas-Areco, supra note 64, para 74; Case of Goiburú et al. Judgment of September 22, 2006. Series C No. 153, para. 88; Case of Servellón-García et al., supra note 14, para. 108; Case of Montero Aranguren et al. (Detention center of Catia), supra note 31, para. 66; Case of Ximenes-Lopes, supra note 60, para. 177; Case of the "Mapiripán Massacre", supra note 8, paras. 232-234; Case of Juan Humberto Sánchez. Judgment of June 7, 2003. Series C No. 99, paras. 111-112; Case of Myrna Mack-Chang, supra note 7, paras. 156-157; Case of the “Street Children” (Villagrán Morales et al.), supra note 58, para. 125; Case of Godínez-Cruz. Judgment of January 20, 1989. Series C No. 5, para. 175, and Case of Velásquez-Rodríguez. Judgment of July 29, 1988. Series C No. 4, paras. 166 and 176. 76 Cf. Case of Juan Humberto Sánchez, supra note 75, para. 112. See also Case of Miguel Castro-Castro Prison, supra note 14, para. 256, and Case of Vargas Areco, supra note 64, para. 77. Similarly, see also ECHR, Erdogan and Others v. Turkey, supra note 66, paras. 88-89; ECHR, Kakoulli v. Turkey, supra note 66, paras. 122-123, and ECHR, Nachova and Others v. Bulgaria [GC], nos. 43577/98 and 43579/98, paras. 111-112, 6 July 2005. 77 Cf. ECHR, Sergey Shevchenko v. Ukraine, no. 32478/02, para. 65, 4 April 2006; ECHR, Tanis and Others v. Turkey, no. 65899/01, para. 204, 2 August 2005, and ECHR, Isayeva v. Russia, no. 57950/00, para. 214, 24 February 2005. 78 Cf. Case of Montero Aranguren et al. (Detention center of Catia), supra note 31, para. 83, and Case of BaldeónGarcía. supra note 60, para. 97. Similarly, see also ECHR, Erdogan and Others v. Turkey, supra note 66, para. 68; ECHR, Makaratzis v. Greece [GC], no. 50385/99, para. 59, 20 December 2004, and ECHR, McCann and Others v. the United Kingdom, supra note 66, para. 150. 79 Cf. Case of the “Mapiripán Massacre”, supra note 8, para. 219; Case of the Pueblo Bello Massacre, supra note 61, para. 144; Case of Baldeón García, supra note 61, para. 97, and Case of Montero Aranguren et al. (Detention center of Catia), supra note 31, para. 83. 80 Cf. Provisional Report on the world situation regarding extrajudicial, summary and arbitrary detention presented by Philip Alston, Special Rapporteur. United Nations General Assembly. (Doc. A/61/311), LIX period of sessions, September 5, 2006, para. 36.