10 and international decisions. In Article 12, said International Convention sets forth that, in the event a report is filed with the relevant authorities, they “shall undertake without delay a thorough and impartial investigation,” and “appropriate steps shall be taken, where necessary, to ensure that the complainant, witnesses, relatives of the disappeared person and their defence counsel [...] are protected.”25 Furthermore, in the absence of a formal complaint, the authorities shall undertake an investigation ex officio.26 In addition, States Parties must ensure that the aforesaid authorities “[h]ave the necessary powers and resources to conduct the investigation effectively, including access to the documentation and other information relevant to their investigation.”27 Finally, each State Party must take: the necessary measures to prevent and sanction acts that hinder the conduct of an investigation. It shall ensure, in particular, that persons suspected of having committed an offence of enforced disappearance are not in a position to influence the progress of an investigation by means of pressure or acts of intimidation or reprisal aimed at the complainant, witnesses, relatives of the disappeared person or their defence counsel, or at persons participating in the investigation.28 30. That the obligation to investigate may not be performed rashly; rather, it must be conducted in accordance with the standards set by international laws and precedents, according to which investigations should be prompt, thorough, impartial and independent. 31. That, in light of the foregoing, the Court considers that it is essential for the State to provide specific information regarding the measures adopted in order to promptly and fully comply with its obligations to locate the mortal remains of Mr. Bámaca-Velásquez and to investigate the facts of this case, identify and punish those responsible for the violations and, specifically, in relation to the matters described below. 32. That, firstly, within two months, the State must provide information about the status and content of the criminal file concerning the forced disappearance of Efraín Bámaca-Velásquez. 33. That, secondly, and in light of the allegations made during the private hearing as well as the findings set forth in the Judgments delivered by the Court in the instant case, the State must inform the Tribunal the number and characteristics of the procedural steps being taken in order to investigate systematic patterns and the responsibility of the respective military chains of command, specifically in relation to the Case of Bámaca-Velásquez. To that end, in the relevant report, the State must refer, inter alia, to: a) 25 the measures adopted to conduct the exhumation at Las Cabañas military detachment, in the hamlet of La Montañita, Municipality of Tecún Umán, Department of San Marcos; Cf. International Convention for the Protection of All Persons from Enforced Disappearance, Art. 12(1). 26 12(2). Cf. International Convention for the Protection of All Persons from Enforced Disappearance, Art. 27 Cf. International Convention for the Protection of All Persons from Enforced Disappearance, Art. 12(3)(a) 28 Cf. International Convention for the Protection of All Persons from Enforced Disappearance, Art. 12(4).