93 obligation),247 under their duty to ensure full and free exercise of the rights by all persons under their jurisdiction.248 This active protection of the right to life by the State involves not only its legislators, but all State institutions, and those who must protect security, be these its police forces or its armed forces.249 Therefore, the States must adopt all necessary measures, not only to prevent, try, and punish deprivation of life as a consequence of criminal acts, in general, but also to prevent arbitrary executions by its own security agents.250 154. In the sub judice, case, it has been established that the State itself fostered a practice of selective summary executions (supra paras. 134.10 and 134.11), a situation that is totally contrary to the duty of the State to respect and ensure the right to life. 155. The Court also deems it proven that at the time of the facts in Guatemala there were no effective mechanisms to investigate violations of the right to life, for which reason there was a climate of impunity regarding human rights violations (supra para. 134.13). Likewise, the CEH stated in its final conclusions: [t]he weakness of the justice system, absent in vast areas of the country before the armed conflict, became more acute when the judiciary bent to the requirements imposed by the prevailing model of national security. The CEH concludes that, by tolerating or directly participating in the impunity that provided material coverage for the very basic violations of human rights, the bodies of the justice system became ineffective in one of their fundamental functions of protection of the individual vis-à-vis the State, and they lost all credibility as guarantors of legality in force. They allowed impunity to become one of the most important mechanisms to generate and maintain the climate of terror.251 156. In cases of extra-legal executions, it is essential for the States to effectively investigate deprivation of the right to life and to punish all those responsible, especially when State agents are involved, as not doing so would create, within the environment of impunity, conditions for this type of facts to occur again, which is contrary to the duty to respect and ensure the right to life . 157. In this regard, safeguarding the right to life requires conducting an effective official investigation when there are persons who lost their life as a result of the use of force by agents of the State.252 In this connection, the European Court of Human Rights has stated that: 247 Cf. Bulacio Case, supra note 9, para. 111; Juan Humberto Sánchez Case, supra note 9, para. 110; and “Street Children” Case (Villagrán Morales et al.), supra note 8, para. 139. 248 Cf. Bulacio Case, supra note 9, para. 111; Juan Humberto Sánchez Case, supra note 9, para. 110; and Cantoral Benavides Case. Reparations (Art. 63(1) American Convention on Human Rights). Judgment of December 3, 2001. Series C No. 88, para. 69. 249 Cf. Juan Humberto Sánchez Case, supra note 9, para. 110. 250 Cf. Juan Humberto Sánchez Case, supra note 9, para. 110; Bámaca Velásquez Case. Judgment of November 25, 2000. Series C No. 70, para. 172; and “Street Children” Case (Villagrán Morales et al.), supra note 8, paras. 144 to 145. 251 Cf. report by the Comisión para el Esclarecimiento Histórico, “Guatemala, memoria del silencio” in June, 1999, Conclusions, page 35. 252 Cf. Juan Humberto Sánchez Case, supra note 9, para. 112.