unpunished (supra para. 61), in violation of the obligation to guarantee the right to personal integrity. 3. Actions subsequent to the events: due diligence and humane treatment in relation to the obligation to guarantee the rights to life and to personal integrity 99. The Court will now examine the arguments concerning the obligation to guarantee the rights to life and personal integrity without discrimination, in the following sections: (a) due diligence in the investigations; (b) the treatment of the survivors, and (c) the treatment of the deceased. 100. The Court observes that, according to the Principles on the Use of Force, if anyone is injured owing to the use of force, assistance and medical aid should be ensured and rendered, and relatives or close friends should be notified at the earliest possible moment. 139 In addition, the incident should be reported promptly, and reports should be subject to review by administrative and prosecutorial authorities. Similarly, the facts should be investigated in order to determine the level and means of participation of all those who intervened, either directly or indirectly, thereby establishing the corresponding responsibilities.140 a) Due diligence 101. The general prohibition for State officials to arbitrarily deprive life would be ineffective if no procedures existed to verify the legality of the use of lethal force exercised by State agents.141 The Court has understood that the general obligation to guarantee the human rights established in the Convention, contained in Article 1(1) thereof, includes the obligation to investigate violations of the substantive right that must be safeguarded, protected or guaranteed.142 This general obligation is particularly significant in cases where lethal force has been used. As soon as the State is aware that its security agents have used firearms with deadly consequences, it is obliged to initiate ex officio and without delay, a serious, independent, impartial and effective investigation143 (infra paras. 183 to 186). This obligation is a fundamental and conditioning element for the protection of the right to life that is negated in these situations.144 102. Also, “in cases of extrajudicial executions, it is essential that the States conduct an effective investigation into the deprivation of life and punish all those responsible, especially when State officials are involved; otherwise they would be creating, in a climate of impunity, the conditions for these facts to be repeated, which is contrary to the obligation to respect and guarantee the right to life.145 In addition, if acts that violate human rights are not 139 Cf. Principles on the Use of Force, Principle No. 5, paragraphs (c) and (d). 140 Cf. Principles on the Use of Force, Principles Nos. 6 and 22. 141 Cf. Case of Montero Aranguren et al. (Retén de Catia) v. Venezuela, supra, para. 79, and Case of Zambrano Vélez et al. v. Ecuador, supra, para. 88. 142 Cf. Case of the Pueblo Bello Massacres v. Colombia. Judgment of January 31, 2006. Series C No. 140, para. 142, and Case of González et al. (Cottonfiield) v. Mexico. Preliminary objection, merits, reparations and costs. Judgment of November 16, 2009. Series C No. 205, para. 287. 143 Cf. Case of Ximenes Lopes v. Brazil. Merits, reparations and costs. Judgment of July 4, 2006. Series C No. 149, para. 148, and Case of Uzcátegui et al. v. Venezuela, supra, para. 226. 144 Cf. Case of Zambrano Vélez et al. v. Ecuador, supra, para. 88, and Case of the Barrios Family v. Venezuela, supra, para. 49. 145 Cf. Case of Myrna Mack Chang v. Guatemala. Merits, reparations and costs. Judgment of November 25, 2003. Series C No. 101, para. 156, and Case of the Barrios Family v. Venezuela, supra, para. 176. 31