6 imposed sentence12 or from sentencing a convicted offender to minimum punishment, which is wholly disproportionate to the gravity of the crime,13 among others. 15. That ending impunity, by all legal means available, is an essential factor in eradicating crimes such as extrajudicial executions.14 A proceeding pursued until its conclusion and achieving its intended purpose is the clearest sign that human rights violations will not be tolerated, contributes to provide reparations to the victims and shows society that justice has been served. 16. That the Court has held that the duty to investigate must not be regarded by the State as a mere formality preordained to be ineffective, or as a mere pursuit of private interests, dependent on the initiative of the victims or their next of kin or upon evidence offered by private individuals.15 Therefore, an effective investigation must be capable of yielding results or providing appropriate responses to violations of the rights enshrined in the Convention. 17. That in order to determine whether an investigation is effective, the Court may resort to international standards and documents that address several aspects of the investigation into human rights abuses, such as the United Nations Principles on the effective prevention and investigation of extra-legal, arbitrary and summary executions, contained in the United Nations Manual on the Effective Prevention and Investigation of Extra-Legal, Arbitrary and Summary Executions (Minnesota Protocol).16 18. That the Inter-American Court has specified that the discovery of the truth within the framework of the duty to investigate an alleged extrajudicial execution should be sought from the early stages of the investigation process with great determination. In this regard, State authorities conducting an investigation into an extrajudicial, arbitrary or summary execution must, inter alia, a) identify the victim; b) recover and preserve evidentiary material related to the death; c) identify possible witnesses and obtain statements from them concerning the death under investigation; d) determine the cause, manner, location and time of death, as well as any pattern or practice that may have brought about the death, and e) distinguish between natural death, accidental death, suicide and homicide. In addition, it is essential that a thorough investigation of the crime scene be conducted and rigorous autopsies and 12 Cf. Case of Valle-Jaramillo et al. v. Colombia, supra note 5, para. 165, and Case of the “Street Children” (Villagrán-Morales et al.) v. Guatemala, supra note 5, Considering clause No. 20. 13 Cf. Case of Vargas-Areco v. Paraguay, supra note 6, paras. 106 to 109, and Case of the “Street Children” (Villagrán-Morales et al.) v. Guatemala, supra note 5, Considering clause No. 20. 14 Cf. Case of the Ituango Massacres v. Colombia. Preliminary Objection, Merits, Reparations, and Costs. Judgment of July 1, 2006. Series C No. 148, para. 299; Case of Vargas-Areco v. Paraguay, supra note 6, para. 81, and Case of the “Street Children” (Villagrán-Morales et al.) v. Guatemala, supra note 5, Considering clause No. 21. 15 Cf. Case of Velásquez-Rodríguez v. Honduras, supra note 8, para. 177; Case of the “Street Children” (Villagrán-Morales et al.) v. Guatemala, supra note 5, Considering clause No. 22, and Case of Kawas-Fernández v. Honduras. Merits, Reparations and Costs. Judgment of April 3, 2009. Series C No. 19, para. 101. 16 Cf. Case of Juan Humberto Sánchez v. Honduras. Preliminary Objection, Merits, Reparations and Costs. Judgment of June 7, 2003. Series C No. 99, para. 127; Case of Zambrano-Vélez et al. v. Ecuador. Merits, Reparations, and Costs. Judgment of July 4, 2007. Series C No. 166, para. 121, and Case of the “Street Children” (Villagrán-Morales et al.) v. Guatemala, supra note 5, Considering clause No. 23.