under that jurisdiction for approximately two months until, following different remedies presented by the petitioners, the case was transferred to the ordinary criminal courts. Under the case law of the Commission and the Court, the mere application of military criminal justice in a case involving serious violations of human rights is incompatible with the American Convention. Furthermore, in this case, both the CEH and MINUGUA pronounced on the concrete effects of the lack of independence and impartiality on the part of those authorities. Specifically, both bodies underscored that “members of the Army tried to exonerate those responsible” and that military judges consulted defense attorneys on a variety of procedural decisions. The IACHR considers that the deficiencies and irregularities in the initial stage of the investigation can generate effects throughout the course of the investigation and criminal proceedings. 129. In light of the foregoing, the IACHR concludes that during the time that the investigation was under military criminal jurisdiction, the State breached its obligation to conduct an independent and impartial investigation of the facts, in violation of the rights to a fair trial and judicial protection recognized at Articles 8(1) and 25(1) the American Convention, in connection with Article 1(1) of that instrument, to the detriment of the surviving victims and the next of kin of all the victims. 3.2 Duty to investigate with due diligence 130. The Court has written whenever the State conducts an investigation because of the alleged perpetration of a crime, it must make sure that it is “oriented at a specific purpose: the determination of the truth and the investigation, finding, arrest, prosecution and, if applicable, punishment of those responsible for the events.”202 To ensure this, the investigation should be undertaken utilizing all the legal means available.203 131. In that connection, the IACHR recalls that states have the obligation to act with all diligence from the very first stages of a proceeding.204 That is because the first investigative steps are key components "for an appropriate development of the judicial investigation, especially in the face of a fact that has cost a person's life.”205 Accordingly, acts of obstruction of justice, hindrances, or problems of non-cooperation with the authorities that have hampered or are hampering clarification of the case constitute a violation of the right to a fair trial.206 132. Thus, in the present case, it must be examined whether the State conducted investigations with due diligence to identify those responsible for the events by gathering proof and other evidence. Regarding this, it must be stressed that this duty of due diligence applies to other investigative activities prior to court proceedings, because it is not possible to conduct proceedings efficiently and effectively if the investigative phase has not been carried out with the characteristics mentioned in the preceding paragraphs. Thus, the Court has found, "All these requirements, together with criteria of independence and impartiality also extend to the non-judicial bodies responsible for the investigation prior to the judicial proceedings.”207 202 IACHR. Case 11.576, Report 33/13, Admissibility and Merits, José Luis García Ibarra and family, Ecuador, July 10, 2013, para. 154. I/A Court H.R., Case of Kawas-Fernández v. Honduras. Merits, Reparations and Costs. Judgment of April 3, 2009. Series C No. 196, par. 101. 203 IACHR. The Right to Truth in the Americas, OEA/Ser.L/V/II.152, August 13, 2014, para. 79. I/A Court H.R., Case of GarcíaPrieto et al. v. El Salvador. Preliminary Objections, Merits, Reparations and Costs. Judgment of November 20, 2007. Series C No. 168, par. 101. 204 I/A Court H.R. Case of Zambrano-Vélez et al. v. Ecuador. Merits, Reparations and Costs. Judgment of July 4, 2007. Series C No. 166, par. 121. 205 I/A Court H.R., Case of Myrna Mack Chang v. Guatemala. Judgment of November 25, 2003. Series C No. 101, par. 167. IACHR, Report No. 37/00, Case 11.481, Merits, Monsignor Oscar Arnulfo Romero y Galdámez, El Salvador, April 13, 2000, par. 85. 206 IACHR, Case 12.788, Report No. 6/14, Merits, Members of the Village of Chichupac and Neighboring Communities of the Municipality of Rabinal, Guatemala, April 2, 2014, par. 290. 207 133. I/A Court H.R., Case of Cantoral-Huaman�� and García-Santa Cruz v. Peru. Judgment of July 10, 2007. Series C No. 167, par. 29