99 283. Regarding the alleged failure to investigate the acts of torture perpetrated against Gladys Espinoza on August 5, 1999, in the Yanamayo Prison, the Court notes that, in his Report on the Yanamayo Prison, Puno of August 25, 1999, the Ombudsman described the violence used against Gladys Espinoza and the injuries that she suffered, and indicated that four other female inmates were subjected to sexual violence on the same occasion (supra paras. 209 and 210). In addition, in this report, the Ombudsman affirmed that the “information available to him […] allowed [him] to conclude that during the inspection of August 5, […] the police agents, using disproportionate force, ill-treated five female inmates, [facts that t]he said police authorities have not only denied […], but have also systematically tried to conceal.” 469 Lastly, the Ombudsman recommended that an investigation be opened to identify and punish those responsible for the said incident. 284. Consequently, the Court finds that the State was aware of the possible perpetration against Gladys Espinoza of acts that could constitute cruel and inhuman treatment or torture by DINOES personnel as of at least August 25, 1999, the date of the above-mentioned report of the Ombudsman (supra para. 209); nevertheless, it did not open any investigation in this regard until 2012 (supra para. 85). Furthermore, the said report indicated that, in the context of the said inspection of August 5, 1999, the other women who were assaulted alleged that they had been subjected to sexual violence, which constitutes sufficient evidence to establish that the State should have also opened an investigation with a gender perspective (supra para. 210) into the acts perpetrated against Gladys Espinoza. This obligation also arises from the Convention of Belém do Pará, which Peru ratified on June 4, 1996 (supra para. 18). B.1.4. Conclusion on the absence of an investigation from 1993 to 2012 285. Based on the foregoing, the Court considers that the State should have opened an investigation, ex officio, immediately after April 18, 1993, into the acts of torture perpetrated against Gladys Espinoza during her arrest, and subsequently on the premises of the DIVISE and the DINCOTE (supra para. 245). The State should also have opened an investigation into the acts of sexual violence perpetrated against her, at least, following April 28, 1993, the date on which APRODEH filed the corresponding complaints before the Special Prosecution Unit of the Ombudsman’s office (supra para. 245). Similarly, the Court considers that the State should have opened an investigation promptly after August 25, 1999, into the acts of torture and the possible existence of sexual violence against Gladys Espinoza within the Yanamayo Prison on August 5, 1999 (supra para. 283). Nevertheless, it was not until April 16, 2012, that the Third Supranational Criminal Prosecutor opened a criminal investigation into these facts, which is currently at the trial stage (supra para. 243). 286. The Court notes that the start of the investigation in 2012 signified an unjustified delay of approximately 19 years in relation to the facts that occurred in the DIVISE and DINCOTE in 1993, and approximately 13 years in relation to the facts that occurred in the Yanamayo Prison in 1999, and that the proceedings are still underway. In this regard, the Court recalls that the lack of diligence means that, as time passes, the possibility of obtaining and presenting pertinent evidence to clarify the facts and determine the corresponding responsibilities is adversely affected, and the State has thereby contributed to their impunity. 470 Thus, it is 469 Report of the Peruvian Ombudsman on the Yanamayo Prison, Puno, of August 25, 1999 (evidence file, folios 1580 to 1601). 470 Cf. Case of Ibsen Cárdenas and Ibsen Peña v. Bolivia. Merits, reparations and costs. Judgment of September 1, 2010 Series C No. 217, para. 172, and Case of the Human Rights Defender et al. v. Guatemala, supra, para. 214. The Court has defined impunity as the total absence of investigation, pursuit, capture, prosecution and conviction of those responsible for human rights violations. Cf. Case of the “White Van” (Paniagua Morales et al.) v. Guatemala. Preliminary objections. para. 173, and Case of the Human Rights Defender et al. v. Guatemala, supra, para. 214.