29 127. It is for this reason that, as soon as the State realizes that its Security Forces have used their firearms and that such use had lethal consequences, the State has the obligation to initiate, ex 151 officio and without delay, a serious, independent, impartial and effective investigation. This is derived from the State’s obligation “to see that their security forces, which are entitled to use legitimate force, 152 respect the life of the individuals under their jurisdiction.” 128. Moreover, in cases where extrajudicial killings are alleged, […] it is essential that States effectively investigate the deprivation of the right to life, and in its case, punish all those responsible, especially when state agents are involved, since on the contrary, it would be creating, within an environment of impunity, the conditions necessary for the repetition of this type of facts, which is contrary to the duty to respect and guarantee the right to life. Besides, if the acts that violate human rights are not investigated seriously, they would in some 153 way, result aided by public power, which compromises the State’s international responsibility . 129. The United Nations Manual on the Effective Prevention and Investigation of Extra-legal, Arbitrary and Summary Executions refers to the principles of investigation that must be observed when a death is believed to have been caused by an extrajudicial execution. The European Court of Human Rights, for its part, has specified the content of an effective investigation designed to evaluate the lawfulness of the lethal use of force. In the words of that Tribunal, […] The essential purpose of such investigation is to secure the effective implementation of the domestic laws which protect the right to life and, in those cases involving state agents or bodies, to ensure their accountability for deaths occurring under their responsibility. The investigation must be independent, accessible to the victim’s family, carried out with reasonable promptness, and effective in the sense that it is capable of leading to a determination of whether the force used in such cases was or was not justified in the circumstances or was illegal, and must permit a degree 154 of public scrutiny of the investigation and its results. 130. The European Court has determined that given the importance of protecting the right to life, its deprivation must be subject to the most careful scrutiny, taking into consideration not only the 155 actions of state agents, but also all circumstances surrounding the case. 131. In the case of Manuel Stalin Bolaños v. Ecuador, the Inter-American Commission held that 151 Inter-Am. Ct. H.R., Case of Zambrano Vélez et al v. Ecuador. Merits, Reparations and Costs. Judgment of July 4, 2007. Series C No. 166, para. 88; Inter-Am. Ct. H.R., Case of Juan Humberto Sánchez v. Honduras. Judgment of June 7, 2003. Series C No. 99, para. 112. See also Case of the Miguel Castro Castro Prison v. Peru. Judgment of November 25, 2006. Series C No. 160, para. 256, and Inter-Am. Ct. H.R., Case of Vargas Areco v. Paraguay. Judgment of September 26, 2006. Series C No. 155, para. 77. In a similar sense, see also ECHR, Erdogan and Others v. Turkey, 25 April 2006, no. 19807/92, paras. 122-123, and ECHR, Nachova and Others v. Bulgaria [GC], nos. 43577/98 and 43579/98, paras. 111-112, 6 July 2005. See also, IACHR, Report on Citizen Security and Human Rights, OEA/Ser.L/V/II., Doc. 57, December 31, 2009, para. 120. 152 Inter-Am. Ct. H.R., Case of Zambrano Vélez et al v. Ecuador. Merits, Reparations and Costs. Judgment of July 4, 2007. Series C No. 166, para. 81; Inter-Am. Ct. H.R., Case of Montero Aranguren et al (Detention Center of Catia) v. Venezuela. Judgment of July 5, 2006. Series C No. 150, para. 66. See also Inter-Am. Ct. H.R., Case of the Miguel Castro Castro Prison v. Peru. Judgment of November 25, 2006. Series C No. 160, para. 238, and Inter-Am. Ct. H.R., Case of Servellón García et al v. Honduras. Judgment of September 21, 2006. Series C No. 152, para. 102. 153 Inter-Am. Ct. H.R., Case of Servellón García et al v. Honduras. Judgment of September 21, 2006. Series C No. 152, para. 123; Inter-Am. Ct. H.R., Case of Baldeón García v. Peru. Judgment of April 6, 2006. Series C No. 147, para. 91; Inter-Am. Ct. H.R., Case of the Pueblo Bello Massacre v. Colombia. Judgment of January 31, 2006. Series C No. 140, para. 145; Inter-Am. Ct. H.R., Case of the “Mapiripán Massacre” v. Colombia. Judgment of September 15, 2005. Series C No. 134, paras. 137 and 232. 154 155 ECHR. Hugh Jordan v. the United Kingdom, no. 24746/94 para. 105-109, 4 May 2001. ECHR, Case of Isayeva, Yusupova and Bazayeva v. Russia, Application nos. 57947/00, 57948/00 and 57949/00, Judgment of 24 February, 2005, para. 170. ECHR, Case of Nachova and others v. Bulgaria, Application nos. 43577/98 and 43579/98, Judgment of 6 July, 2005, para. 93.