72 right to life to be interpreted and applied in a way that ensures that its safeguards are practical and effective (effet utile).167 130. The Court has indicated in its consistent case law that compliance with the obligations imposed by Article 4 of the American Convention, in relation to Article 1(1) thereof, presumes not only that no one shall be deprived of their life arbitrarily (negative obligation), but also, in light of their obligation to ensure the full and free exercise of all human rights, that States adopt all appropriate measures to protect and preserve the right to life (positive obligation) of those subject to their jurisdiction.168 131. This active protection of the right to life by the State involves not only its legislators, but also all State institutions and those who should protect security, whether they are its police or its armed forces. Consequently, the State must adopt the necessary measures, not only at the legislative, administrative and judicial levels by the issue of penal norms and the establishment of a justice system to prevent, eliminate and punish the deprivation of life as a result of criminal acts, but also to prevent and protect individuals from the criminal acts of other individuals, and investigate such situations effectively.169 132. In this case, it has been proved (supra para. 125(36) to 125(40) and 125(55) to 125(79)) and the State has acknowledged that, in June 1996 and as of October 1997, in the municipal districts of La Granja and El Aro, respectively, both located in the Municipality of Ituango, Department of Antioquia, Colombia, paramilitary groups perpetrated successive armed incursions, murdering defenseless civilians. The State’s responsibility for these acts, which occurred in the context of a pattern of similar massacres, arises from the acts of omission, acquiescence and collaboration by members of the law enforcement bodies based in this municipality. 133. As the State has acknowledged (supra paras. 63 and 64), it has been proved that State agents were fully aware of the terrorist activities perpetrated by these paramilitary groups on the inhabitants of La Granja and El Aro. Far from taking measures to protect the population, members of the National Army not only acquiesced to the acts perpetrated by the paramilitary groups, but at times collaborated with and took part in them directly. Indeed, the participation of State agents in the armed raids was not limited to facilitating the entry into the region of the paramilitary groups, but they also failed to assist the civilian population during the incursions, leaving them totally defenseless. This collaboration between paramilitary groups and State agents resulted in the violent death of 19 inhabitants of La Granja and El Aro. 167 Cf. Case of Baldeón García, supra note 5, para. 83; Case of Hilaire. Preliminary Objections. Judgment of September 1, 2001. Series C No. 80, para. 83; Case of the Constitutional Court. Competence. Judgment of September 24, 1999. Series C No. 55, para. 36. Likewise, cf. Eur.C.H.R., McCann and Others v. the United Kingdom, Judgment of 27 September 1995, Series A no. 324, paras. 146-147. 168 Cf. Case of Baldeón García, supra note 5, para. 84; Case of the Sawhoyamaxa Indigenous Community, supra note 9, para. 152; and Case of the Pueblo Bello Massacre, supra note 9, para. 120. Likewise, cf. Eur.C.H.R., L.C.B. v. the United Kingdom, Judgment of 8 June 1998, para. 36. 169 Cf. Case of Baldeón García, supra note 5, para. 85; Case of the Sawhoyamaxa Indigenous Community, supra note 9, para. 153; and Case of the Pueblo Bello Massacre, supra note 9, para. 120.