56 the Court will proceed to determine their legal definition and, where appropriate, to determine whether the State violated the rights recognized in the American Convention and the ICPPT. 149. In this regard, the Court finds it relevant to recall the standards it has used for assessing the evidence in this type of case. Thus, regarding the statements made by presumed victims, the Court has considered that they usually abstain from denouncing acts or torture or illtreatment out of fear, especially if they are detained in the place where these occurred, 237 and that it is not reasonable to require the victims of torture to describe all the presumed illtreatment they have suffered each time they make a statement. 150. In cases of alleged sexual violence, the Court has indicated that, generally, sexual assaults are characterized by occurring in the absence of anyone other than the victim and the assailant or assailants. Given the nature of this type of violence, the existence of graphic or documentary evidence cannot be expected and, consequently, the victim’s statement constitutes fundamental proof of the fact. 238 Also, when examining such statements, it must be borne in mind that sexual abuse corresponds to a type of offense that the victim does not usually report, 239 owing to the stigma that frequently results from this type of complaint. The Court has also taken into account that the statements made by victims of sexual violence relate to an occasion that was very traumatic for them, and its impact may lead to a certain lack of precision when remembering it.240 Therefore, the Court has noted that the lack of precision in statements relating to sexual violence, or the mention of some of the alleged facts in only some of them, does not mean that such statements are false or that the facts recounted are untrue. 241 151. In addition, the Court recalls that the evidence obtained by medical examinations plays a crucial role in investigations involving detainees, and in cases in which they allege illtreatment. 242 Thus, allegations of ill-treatment in police custody are extremely difficult to substantiate by the victim, if he or she was isolated from the external world, without access to doctors, lawyers, family or friends who could provide support and gather the necessary evidence. 243 Therefore, the judicial authorities have the duty to ensure the rights of detainees, which entails obtaining and preserving any evidence that may substantiate the acts of torture, including medical examinations. 244 152. It is also important to underline that, in cases in which supposed torture or ill-treatment is alleged, the time that passes before the corresponding medical appraisals is significant for the 237 Cf. Case of Bayarri v. Argentina. Preliminary objection, merits, reparations and costs. Judgment of October 30, 2008. Series C No. 187, para. 92, and Case of J. v. Peru, supra, para. 337. 238 Cf. Case of Fernández Ortega et al. v. Mexico. Preliminary objection, merits, reparations and costs. Judgment of August 30, 2010. Series C No. 215, para. 100, and Case of J. v. Peru, para. 323. 239 Cf. Case of Rosendo Cantú et al. v. Mexico. Preliminary objection, merits, reparations and costs. Judgment of August 31, 2010. Series C No. 216, para. 95, and Case of J. v. Peru, supra, para. 323. 240 Cf. Case of J. v. Peru, supra, para. 325. Similarly, see Case of Fernández Ortega et al. v. Mexico, supra, para. 105, and Case of Rosendo Cantú et al. v. Mexico, supra, para. 91. 241 Cf. Case of Cabrera García and Montiel Flores v. Mexico, supra, para. 113, and Case of J. v. Peru, supra, para. 325. 242 Cf. EHCR, Korobov v. Ukraine, No. 39598/03, Judgment of 21 July 2011, para. 69, Salmanoğlu and Polattaş v. Turkey, No. 15828/03, Judgment of 7 March 2009, para. 79, and Case of J. v. Peru, supra, para. 333. 243 Cf. Case of J. v. Peru, supra, para. 333. Also, EHCR, Case of Aksoy v. Turkey, No. 21987/93, Judgment of 18 December 1996, para. 97, and Case of Eldar Imanov and Azhdar Imanov v. Russia, No. 6887/02, Judgment of 16 December 2010, para. 113. 244 Cf. Case of Bayarri v. Argentina, supra, para. 92, and Case of J. v. Peru, supra, para. 333. See also, Office of the United Nations High Commissioner for Human Rights, Istanbul Protocol (Manual on the Effective Investigation and Documentation of Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment), New York and Geneva, 2001, para. 77, and Case of Eldar Imanov and Azhdar Imanov v. Russia, No. 6887/02, Judgment of 16 December 2010, para. 113.