This consideration is relevant in light of the principle of proportionality of punishment, in keeping with the legal precedent of the Court cited above. 123. Lastly, the Commission notes that the State did not investigate potential liability of the other military agents, who were present at the scene of the crime. Regarding this, the IACHR takes into account what was consistently indicated during the proceeding and in the claim presented at the national level with respect to the obstacles imposed by the Armed Forces to impede helping Mirey Trueba and taking him immediately to a health facility. Moreover, it has been consistently denounced that such agents also mistreated his brother and Mr. Jiménez. Such mistreatment was denounced by Vidal Trueba in his declaration. Given the consistency, specificity and context of what was denounced and in absence on investigation or evidence on the part of the State, the Commission concludes that other members of the security forces participated in the human rights violations that took place on August 22, 1998. Therefore, the competent authorities necesarilly had the obligation to investigate the death of Mirey Trueba in the context of the other facts denounced. 124. Based on all of the foregoing, the Commission concludes that the Mexican State breached its obligation to investigate the death of Mirey Trueba Arciniega with due diligence and, consequently, violated the right to a fair trial and judicial protection, provided for in Article 8.1 and 25.1 of the American Convention, in connection with the obligations set forth in Article 1.1 of this same instrument, to the detriment of his next of kin. 3. Access to justice and access to information for the family over the course of the proceedings 125. The Commission underscores that it is the obligation of the State to ensure that, at all of the respective stages of investigations and judicial proceedings, victims are able to make their claims, submit evidence and for that evidence to be examined fully and seriously by the authorities before a ruling is made on the facts, criminal liability, punishments and reparations.127 126. In the instant case, the petitioners alleged repeatedly that Mr. Trueba’s next of kin did not have access to the investigations and that the military court where the case was processed was thirty hours away from their place of residence. In response, the State only noted that the hearings conducted during the case were public. The Commission notes that Mexico did not refute the petitioners’ allegations by submitting any evidence to substantiate that the family members did indeed take part in the investigations and had access to the relevant information. The State did not provide any proof that it took the necessary measures to ensure that they were able to travel to the courthouse despite the long distance between it and their residence. 127. Consequently, the Commission finds that access to the case file for Mr. Trueba’s next of kin was limited and this had an impact on their ability to take part and be heard in the investigation and trial. This situation constituted an additional violation, to their detriment, of the right to a fair trial and judicial protection as established in Article 8.1 and 25.1 of the American Convention in connection with the obligations enshrined in Article 1.1 of this same instrument. C. Right to humane treatment of the next of kin (Article 5 of the American Convention in connection with Article 1.1 of the same instrument) 128. Article 5.1 of the American Convention establishes that “Every person has the right to have his physical, mental, and moral integrity respected.” With regard to the next of kin of victims of certain human rights violations, the Inter-American Court has reiterated that such family members can, in turn, be 127 IA Court of HR. Case of the Massacres of Ituango v. Colombia. Judgment of July 1, 2006. Series C No. 148, par. 296; and Case of Ximenes Lopes v. Brazil. Preliminary Objection. Judgment of November 30, 2005. Series C No. 139, par. 193. 24