investigate is an obligation of means and not of results, 646 so that the party alleging their ineffectiveness must prove that this is due to defects, negligence or omissions in the conduct of the investigations, and it is not sufficient to allege their ineffectiveness merely alluding to their current procedural stage. Therefore, the Court does not have sufficient evidence to determine the violation of due diligence in the investigations related to the disciplinary proceedings. e) Conclusions 397. The Court considers that the State is responsible for not having acted with due diligence in the investigations into the members of the Armed Forces and those related to the paramilitary structures, in violation of Articles 8 and 25 of the Convention, in relation to Article 1(1) thereof, to the detriment of the communities displaced from the Cacarica owing to the events of February 1997. B.2. Considerations on the reasonable time 398. The Court recalls that the State made a partial acknowledgement of its responsibility for the violation of the reasonable time in the investigations into the events of this case (supra para. 17). Despite considering that, indeed, the duration of the domestic investigation, as a whole, did not satisfy the criteria of reasonable time referred to in Article 8(1) of the Convention, the Court underlines that, in complex cases, such as this one, it is necessary to take into account the complexity of the evidence, the numerous procedural subjects or the number of victims, the characteristics of the remedies established by domestic law, and the context in which the violation occurred, 647 as well as the nature of the charges, the number of accused, and the political and social situation in the place and at the time the events occurred. 399. This case presumably involves numerous members of the Armed Forces and of the paramilitary groups, including high-ranking officers of the Armed Forces whose activities were confidential owing to the nature of their functions. In addition, hundreds of presumed victims were affected by acts that occurred in the context of the Colombian armed conflict – in a region with difficult access (supra para. 84), and in areas with the presence of illegal armed groups (guerrillas and paramilitaries), which entailed risks for the investigators themselves – which are, as it has been acknowledged, characteristic of systematic actions, and with potential witnesses who have displaced to different parts of the country. Therefore, it is clear that the investigation into the events of this case was extremely complex. This has been acknowledged during these proceedings both by the parties and by the Commission. 400. Regarding the two proceedings undertaken before the National Human Rights and International Humanitarian Law Unit (case files 426 and 2332), it can be observed that the investigations initiated in 1997 encountered significant obstacles owing to the context of organized crime in which the human rights violations that are being examined here occurred. 401. In relation to the investigation in case file 426, up until 2004, the Court was able to verify different actions designed, among other matters, to declare the preliminary investigation open, to order the preventive detention of the accused, and to admit a civil complaint (supra para. 145 and ff.). Regarding this proceeding, neither the Commission nor the representatives have presented information or arguments from which it could be inferred that the decision to preclude the investigation on March 9, 2004, was issued fraudulently, in collusion with the accused, or that there had been a lack of due diligence. Thus, the Court does not have evidence that would allow it to infer an excess of the reasonable time by the authorities with regard to 646 218. Cf. Case of Velásquez Rodríguez v. Honduras, Merits, para. 177, and Case of Mendoza et al. v. Argentina, para. 647 Cf., inter alia, Case of the Pueblo Bello Massacre v. Colombia, para. 184, Case of the Ituango Massacres v. Colombia. Preliminary objection, merits, reparations and costs, para. 293, Case of Valle Jaramillo et al. v. Colombia, para. 156, and Case of Furlan and family members v. Argentina, para. 156. 127