87. In light of this duty, when it comes to the investigation of the death of a person who was in State custody, as in this case, the relevant authorities have a duty to initiate ex officio and without delay, a serious, impartial, and effective investigation. This investigation should be conducted using all available legal means and be aimed at determining the truth and investigation, prosecution, and punishment of those responsible for the facts, especially when they are or may be State agents involved. 95 It is pertinent to note that the duty to investigate is an obligation of means and not results. Nevertheless, it must be assumed by the State as a legal duty and not as a mere formality preordained to be ineffective, or as a mere step effectuated by private interests that depends upon the initiative of the victims or their relatives or their offer of proof. 96 88. The Court has established that the State is responsible, given its condition as guarantor of the rights enshrined in the Convention, for enforcement of the rights to life and personal integrity of every individual who is under its custody. 97 It is possible to consider the State responsible for cruel, inhumane, or degrading treatment suffered by a person who has been in the custody of State agents, or who has died in such circumstances if, in addition, the authorities have not conducted a serious investigation of the facts followed by the prosecution of those who appear to be responsible for them. 98 In this sense, it falls on the State to provide an immediate, satisfactory, and convincing explanation of what happened to a person who was under State custody and to rebut the allegations of its responsibility, through the use of appropriate evidentiary means. 99 95 Cf. Case of Velásquez Rodríguez V. Honduras, supra note 11, para. 177; Case of González et al. (“Cotton Fields”) V. México, supra note 21, para. 290, and Case of Ibsen Cárdenas and Ibsen Peña V. Bolivia, supra note 94, para. 155. 96 Cf. Case of Velásquez Rodríguez V. Honduras, supra note 11, para. 177; Case of Gomes Lund et al. (Guerrilha do Araguaia) V. Brazil, supra note 4, para. 138, and Case of Gelman V. Uruguay, supra note 12, para. 184. 97 Cf. Case of Neira Alegría et al. V. Perú, supra note 35, para. 60; Case of Vélez Loor V. Panamá, supra note 3, para. 198, and Case of Cabrera García and Montiel Flores V. México, supra note 7, para. 134. 98 Cf. Case of the “Street Children” (Villagrán Morales et al.) V. Guatemala, supra note 29, para. 170; Case of Baldeón García V. Perú. Merits, Reparations and Costs. Judgment of April 6, 2006. Series C No. 147, para. 120, and Case of of the Miguel Castro Castro Prison V. Perú, supra note 42, para. 273. Similarly, Cf. C.E.D.H., Case of Yavuz V. Turquía, (No. 67137/01), Judgment of January 10, 2006, para. 38; Case of Aksoy V. Turquía, (No. 100/1995/606/694), Judgment of December 18, 1996, paras. 61 and 62, and Case of Tomasi V. Francia, (No. 12850/87), Judgment of August 27, 1992, paras. 108 a 111. 99 Cf. Case of Juan Humberto Sánchez V. Honduras. Preliminary Objection, Merits, Reparations and Costs. Judgment of June 7, 2003. Series C No. 99, para. 111; Case of Baldeón García V. Perú, supra note 107, para. 120, and Case of of the Miguel Castro Castro Prison V. Perú, supra note 42, para. 273. It is important to include the jurisprudence of the European Court of Human Rights on the subject, which has held that, under Article 3 of the European Convention, which recognizes the right to personal integrity, the State has an obligation to give a "convincing explanation” regarding any injury suffered by a person deprived of liberty. Furthermore, based on a reading of Article 3 of the European Convention in relation to Article 1 of the same instrument, it has established that a formal and effective investigation is required when an individual makes a "plausible claim" that there has been a violation, by a State agent, to one of their rights under Article 3 of the Convention. In the same line, it has established that otherwise the general prohibition of cruel, inhuman and degrading treatment, among others, would be "ineffective in practice," since it would be possible for agents of the State to abuse the rights of those who are 35