59 effective investigation.236 This investigation must be carried out using all available legal means with the aim of discovering the truth. 176. The Court has also indicated that Article 8 of the Convention reveals that the victims of human rights violations, or their next of kin, should have wide-ranging possibilities of being heard and taking part in the respective proceedings, both in order to clarify the facts and punish those responsible, and also to seek due reparation. Furthermore, the Court has indicated that the obligation to investigate and the corresponding right of the alleged victims or the next of kin is not only evident from the treaty-based provisions of international law that are binding for the State Parties, but also arise from domestic law regarding the obligation to investigate ex officio certain unlawful conducts, as well as from the norms that permit the victims or their next of kin to denounce or submit complaints, evidence or petitions, or take any other measure in order to play a procedural role in the criminal investigation so as to establish the truth of the facts.237 177. In cases of violence against women, the general obligations established in Articles 8 and 25 of the American Convention are complemented and enhanced by the obligations arising for States parties from the specific obligations of the Inter-American treaty, the Convention of Belem do Pará. Article 7(b) of this Convention specifically obliges the States parties to apply due diligence to prevent, punish, and eradicate violence against women. Thus, when an act of violence against a woman occurs, it is particularly important that the authorities in charge of the investigation carry it out it in a determined and effective manner, taking into account society’s obligation to reject violence against women and the State’s obligation to eliminate it and to ensure that victims trust the State institutions there for their protection. 178. On other occasions, this Court has defined the guiding principles that must be observed in criminal investigations into human rights violations, and these may include, inter alia: recovery and preservation of probative material in order to assist any potential criminal investigation of the authors; identification of possible witnesses and obtaining their statements, and determination of the cause, form, place and time of the act investigated. In addition, the scene of the crime should be examined thoroughly, and rigorous analysis should be performed by competent professionals, using the most appropriate procedures.238 In cases of violence against women, several international instruments describe and illustrate the enhanced State obligation to investigate them with due diligence.239 Among other requirements, in the course of a criminal investigation for rape: i) the victim’s statement should be taken in a safe and comfortable environment, providing privacy and trust; ii) the victim’s statement should be recorded so as to avoid or limit the need for repetition; iii) the victim should be provided with medical, psychological and hygienic treatment, both on an emergency basis, and continuously if required, under a protocol for such attention aimed at reducing 236 Cf. Case of the Pueblo Bello Massacre v. Colombia. Merits, Reparations, and Costs. Judgment of January 31, 2006. Series C No. 140, para. 143; Case of Perozo et al., v. Venezuela. Excepciones Preliminares, Merits, Reparations and Costs. Judgment of January 28, 2009. Series C No. 195, para. 298, and Case of González et al., (“Cotton Field”), supra note 21, para. 290. 237 Cf. As an example, the Federal Code of Criminal Procedure, Article 141, which recognizes the Rights of the injured party in the preliminary investigation (section A), in the criminal procedure (section B), and during the execution of punishments (section C), and the Criminal Procedure Code of the state of Guerrero, Article 5, first paragraph, which recognizes the right of the victim or the injured party to contribute to the Public Prosecutor, offering the judge, by way of conduct or directly, all the facts available to prove the assertions and amount of harm and detriment caused by the crime. 238 Cf. Case of Juan Humberto Sánchez v. Honduras. Preliminary Exceptions, Merits, Reparations, and Costs. Judgment of June 7, 2003. Series C No. 99, para. 128; Case of Garibaldi, supra note 211, para. 115, and Case of González et al., (“Cotton Field”), supra note 21, para. 300. 239 Cf. United Nations Office of the High Commissioner for Human Rights, Istanbul Protocol, supra note 39, inter alia, paras. 67, 77, 89, 99, 101 to 103, 155, 162, 163, 170, 171, 224, 225, 260, 269, and 290, and W.H.O., Guidelines for medico-legal care for victims of sexual violence, supra note 39, inter alia, pages 17, 30, 31, 34, 39 to 44, and 57 to 74.