64 of protection of the subject of law, either because of his or her personal situation or because of the specific circumstances in which he or she finds himself.261 244. The rights to life and to personal integrity have an essential nature in the Convention. According to its Article 27(2) these rights form part of the non-derogable nucleus of rights, because they cannot be suspended in cases of war, public danger or other threats. 245. Furthermore the Court has established that the right to life plays a fundamental role in the American Convention, since it is the essential assumption for the exercise of the other rights. The States have the obligation to guarantee the creation of the conditions required to ensure that there are no violations of this inalienable right and, in particular, the obligation to prevent violations by its agents. The observance of Article 4, in relation to Article 1(1) of the American Convention, presupposes not only that no person may be deprived of his life arbitrarily (negative obligation), but also requires the States to adopt all appropriate measures to protect and preserve the right to life (positive obligation),262 pursuant to the obligation to ensure to all persons subject to its jurisdiction the full and free exercise of the rights.263 246. With regard to the obligation to ensure the right recognized in Article 5 of the American Convention, this entails the State’s duty to prevent and investigate possible acts of torture or other cruel, inhuman or degrading treatment. In this regard, the Tribunal has indicated that: In the light of the general obligation to guarantee all persons under their jurisdiction the human rights enshrined in the Convention, established in Article 1(1) of the same, along with the right to humane treatment pursuant to Article 5 (Right to Humane Treatment) of said treaty, there is a [S]tate obligation to start ex officio and immediately an effective investigation that allows it to identify, prosecute, and punish the responsible parties, when there is an accusation or well-grounded reason to believe that an act of torture has been committed.264 247. Regarding Article 7(1) of the Convention, this Court has stated that, in general, it embodies the right to personal liberty and security, and that the other paragraphs of Article 7 recognize different guarantees that must be given when depriving someone of their liberty. This recognizes that domestic laws usually affect the right to liberty negatively, by allowing liberty to be deprived or restricted. Therefore, liberty is always the rule and the limitation or restriction is always the exception.265 Consequently, the State must prevent the liberty of the individual being violated by the actions of public officials and private third parties, and must also investigate and punish acts that violate this right. 261 Cf. Case of Baldeón García v. Peru. Merits, Reparations and Costs. Judgment of April 6, 2006. Series C No. 147, para. 81; Case of the Sawhoyamaxa Indigenous Community v. Paraguay. Merits, Reparations and Costs. Judgment of March 29, 2006. Series C No. 146, para. 154; and Case of the Pueblo Bello Massacre v. Colombia. Merits, Reparations and Costs. Judgment of January 31, 2006. Series C No. 140, para. 111. 262 Cf. Case of the “Street Children” (Villagrán Morales et al.) v. Guatemala, supra note 31, para. 144; Case of the Miguel Castro Castro Prison v. Peru, supra note 248, para. 237, and Case of Vargas Areco v. Paraguay. Merits, Reparations and Costs. Judgment of September 26, 2006. Series C No. 155, para. 75. 263 Cf. Case of the Pueblo Bello Massacre v. Colombia, supra note 261, para. 120; Case of the Miguel Castro Castro Prison v. Peru, supra note 248, para. 237, and Case of Vargas Areco v. Paraguay, supra note 262, para. 75. 264 Case of the Miguel Castro Castro Prison v. Peru, supra note 248, para. 345; Case of Vargas Areco v. Paraguay, supra note 262, para. 79, and Case of Bueno Alves v. Argentina. Merits, Reparations and Costs. Judgment of May 11, 2007. Series C No. 164, para. 89. 265 Cf. Case of Chaparro Álvarez and Lapo Íñiguez. v. Ecuador. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 21, 2007. Series C No. 170, para. 53.