36. As a general rule, a criminal investigation should be carried out promptly to protect the interests of the victims, preserve evidence, and furthermore to safeguard the rights of such persons as might be regarded as suspects in the investigation. The Commission regards highly the efforts of the Human Rights Unit of the Prosecutor General’s Office; however, for the purposes of the requirement provided for in Article 46(2) of the American Convention, the failure to detain the vast majority of the participants in the facts of the instant case, coupled with the failure to capture the ringleader and alleged co-architect of the massacre, are an expression of delay and of the unlikelihood that this remedy will be effective.24 As the InterAmerican Court has held, although all criminal investigations must meet a series of legal requirements, the rule of prior exhaustion must never lead to a halt or delay that would render international action in support of the defenseless victim ineffective.25 37. Therefore, given the characteristics of the instant case, the Commission finds that the exception provided in Article 46(2)(c) of the American Convention is applicable, and, therefore, that the requirements prescribed in the American Convention on exhaustion of domestic remedies and, consequently, the six-month deadline for lodging the petition, are not applicable. 38. All that remains is to mention that invocation of the exceptions to the rule of exhaustion of domestic remedies provided in Article 46(2) of the Convention is closely associated with examination of the existence of possible violations of certain rights enshrined therein, such as the guarantees of access to justice. However, Article 46(2), by its nature and purpose, is a self-contained provision vis á vis the substantive provisions contained in the Convention. Therefore, to determine whether or not the exceptions to the rule of exhaustion of domestic remedies provided in said provision are applicable to a particular case requires an examination carried out in advance of and apart from the analysis of the merits of the case, since it depends on a different standard of appreciation to that used to establish whether or not there has been a violation of Articles 8 and 25 of the Convention. It should be clarified that the causes and effects that have prevented exhaustion of domestic remedies in the instant case will be examined, if pertinent, in the report that the IACHR adopts on the merits of the dispute, in order to determine if they do indeed constitute violations of the American Convention. 2. Duplication of proceedings and res judicata 39. According to the record, the subject matter of the petition is not pending in another international proceeding for settlement, nor is the petition substantially the same as one previously studied by the Commission or by another international organization. Accordingly, the requirements set forth in Articles 46(1)(c) and 47(d) have also been met. 3. Nature of the alleged violations 40. The Commission finds that the allegations of the petitioners regarding the violations of the rights to life, humane treatment, and personal liberty allegedly committed against approximately 49 persons in the area of Mapiripán from July 15 to 20, 1997, as well as the delay in the investigation and the failure to prosecute and effectively punish those responsible, could constitute a violation of the rights recognized in Articles 4, 5, 7, 8, and 25, pursuant to Article 1(1) of the American Convention. The Commission finds that the petition meets the requirements set forth in Articles 47(b) and (c) of the American Convention. CONCLUSIONS 41. The Commission finds that it is competent to take up the complaint lodged by the petitioners and that the case is admissible in accordance with the requirements provided in Articles 46 and 47 of the American Convention. 24 See Report on Admissibility Nº 57/00, La Granja, Ituango, October 2, 2000. 25 Inter-Am. Ct.H.R., Velásquez Rodríguez Case, Preliminary Objections, Judgment of June 26, 1987, paragraph 93. 8