148. The Court examined the Expiry Law in the Gelman case (supra para. 42). After that 2011 decision, the State adopted measures that would reestablish the punitive claims of the State (supra paras. 43 and 44). In the present case, however, the State has not defended the compatibility of the Expiry Law with the Convention nor with international law. The Court, therefore, considers that it is not necessary to review its analysis of that law, but rather, since the law had effects on the present case (supra paras. 143 to 145), it must take into consideration the conclusions that the Court has already reached. 149. The Court, therefore, reiterates that the provisions of the Expiry Law that impede an investigation into and the punishment of serious human rights violations lack effectiveness (supra para. 42) due to their manifest incompatibility with the Convention180 and that “in applying the provisions of the Expiry Law (which, for all intents and purposes, constitutes an amnesty law) and thereby impeding the investigation of the facts and the identification, prosecution, and possible punishment of the possible perpetrators of continued and permanent injuries such as those caused by enforced disappearance, the State fails to comply with its obligation to adapt its domestic law set out in Article 2 of the American Convention.”181 This applies to “continuous and permanent violations such as forced disappearances,” as was pointed out in the Gelman case, and to other serious human rights violations, such as extrajudicial executions. With respect to forced disappearances, the Expiry Law implies, in addition to the failure to observe Article 2, the failure to comply, as of May 2, 1996 (supra para. 12), with Article I(d) of the IACFDP. 150. During the period in which the domestic judicial proceedings were interrupted due to the application of the Expiry Law, the State did not comply, to the detriment of the victims in this case (infra para. 195), with its duty to investigate in relation not only to the obligation established in Article 1(1) of the American Convention, but also to that set out in its Article 2, and, where appropriate, in Article I(d) of the IACFDP. B.2.2 Due diligence in the actions B.2.2.1 Regarding the determination of the whereabouts of the disappeared persons 151. The Court notes, in the first place, that in cases of disappeared persons the response of the State is essential to protect the life and integrity of the person affected. Prompt and immediate action on the part of the authorities is absolutely essential from the moment of learning of the disappearance to order and undertake timely and necessary measures directed to determine the whereabouts of the person or the place where he or she might be detained. The investigation, whether judicial or administrative, must be conducted with due diligence in a serious manner in a way that all efforts are systematic and rigorous.182 Arellano et al.), Brazil (Gomes Lund et al.), Uruguay (Gelman) and El Salvador (Massacres of El Mozote and surrounding areas)”. 180 Case of Gelman v. Uruguay. Merits and Reparations, para. 232. 181 Case of Gelman v. Uruguay. Merits and Reparations, para. 240. Cf., Similarly, Case of Velásquez Rodríguez v. Honduras. Merits, paras. 174 and 176; Case of Gudiel Álvarez et al. (“Diario Militar”) v. Guatemala. Merits, Reparations and Costs. Judgment of December 20, 2012. Series C No. 253, para. 334 and Case of Garzón Guzmán et al. v. Ecuador, para. 74. In paragraph 75 of the latter judgment, the Court stated that “while the duty of due diligence in the search is related to the obligation 182 41