117 facts and the sanction of those responsible, and also in seeking fair compensation.239 However, the State is responsible for the effective search for the truth and this does not depend on the procedural initiative of the victim or his next of kin, or on his contribution of evidence.240 Accordingly, it cannot be maintained, as the State has done (supra para. 282(ii)(b)), that, in a case such as this one, the procedural activity of the party concerned should be considered a determinant in defining the reasonableness of the time. It should be recalled that the case involves, inter alia, the extrajudicial execution of 19 persons. In such cases, the Court’s case law is unequivocal: the State has the obligation to initiate ex officio, immediately, a genuine, impartial and effective investigation, which is not undertaken as a mere formality predestined to be ineffective.241 297. This obligation to investigate results from the general undertaking of States Parties to the Convention to respect and ensure the human rights embodied therein; in other words, the obligation established in its Article 1(1), together with the substantive right that must be protected or ensured. Thus, when the right to life is violated, compliance with the obligation to investigate is a central element when determining the State’s responsibility for the failure to respect due judicial guarantees and judicial protection. 298. In this regard, based on the United Nations Manual on the Effective Prevention and. Investigation of Extra-Legal, Arbitrary and Summary Executions, the Court has defined the guiding principles that should be observed when it is considered that a death may be due to extrajudicial execution. The State authorities that conduct an investigation must try, as a minimum, inter alia to: (a) identify the victim; (b) recover and preserve the probative material related to the death to contribute to any possible criminal investigation into those responsible; (c) identify possible witnesses and obtain their statements in relation to the death under investigation; (d) determine the cause, method, place and moment of death, as well any pattern or practice that could have caused the death, and (e) distinguish between natural death, accidental death, suicide and murder. In addition, the scene of the crime must be searched exhaustively, autopsies carried out and human remains examined rigorously by competent professionals using the most appropriate procedures.242 299. On repeated occasions, the Court has established that the State has the obligation to avoid and combat impunity, which the Court has defined as “the absence of any investigation, pursuit, capture, prosecution and conviction of those 239 Cf. Case of Baldeón García, supra note 5, para. 146; Case of the Pueblo Bello Massacre, supra note 9, para. 146; and Case of the “Mapiripán Massacre”, supra note 8, para. 219. 240 Cf. Case of Baldeón García, supra note 5, para. 93; Case of the Pueblo Bello Massacre, supra note 9, para. 144; and Case of the “Mapiripán Massacre”, supra note 8, para. 219. 241 Cf. Case of the Pueblo Bello Massacre, supra note 9, para. 143; Case of the “Mapiripán Massacre”, supra note 8, para. 223; and Case of the Moiwana Community, supra note 12, para. 146. 242 Cf. Case of Baldeón García, supra note 5, para. 96; Case of the Pueblo Bello Massacre, supra note 9, para. 177; and Case of the “Mapiripán Massacre”, supra note 8, para. 224. Likewise, United Nations Manual on the Effective Prevention and. Investigation of Extra-Legal, Arbitrary and Summary Executions, E/ST/CSDHA/12 (1991).