47 is clearly demonstrated. This lack of due diligence is manifested in the unreasonable length of the proceedings; the failure to adopt the necessary measures to protect against the threats which arose during the investigations; the delays, obstacles and obstructions which arose during the proceedings, and the grave omissions in the development of logical lines of investigation. 156. The focal point of analysis of whether the proceedings in this case were effective is whether they complied with the obligation to investigate with due diligence. This obligation requires that the body investigating a violation of human rights use all available means to carry out all such steps and inquiries as are necessary to achieve the goal pursued within a reasonable time.145 The obligation to employ due diligence is particularly stringent and important in the face of the seriousness of the crimes committed and the nature of the rights violated.146 In this sense, all necessary measures must be adopted in order to prevent the systematic patterns that led to the commission of serious human rights violations. 157. In order to examine the diligence employed in the identification of all those responsible for the massacre of The Rochela, the Court deems it important to take into account the factors indicated (supra para. 90, 91, 99, 102, 109, and 111) with regard to: the number of individuals who participated in the massacre, the collaboration and acquiescence of state agents, the motive of the massacre, the direct relationship between the “Los Masetos” paramilitary group and the ACDEGAM paramilitary group and their links to senior commanders of security forces in the area, as well as the fact that during the investigations into the Rochela Massacre, Army personnel obstructed the capture of some individuals (supra para. 172 to 175). 158. In context of the facts of the present case, the principles of due diligence required that the proceedings be carried out taking into account the complexity of the facts, the context in which they occurred147 and the systematic patterns that explain why the events occurred. In addition, the proceedings should have ensured that there were no omissions in gathering evidence or in the development of logical lines of investigation. Thus, the judicial authorities should have borne in mind the factors indicated in the preceding paragraph that denote a complex structure of individuals involved in the planning and execution of the crime, which entailed the direct participation of many individuals and the support or collaboration of others, including State agents. This organizational structure existed before the crime and persisted after it had been perpetrated, because the individuals who belong to it share common goals. 159. According to the results of the investigations into the massacre, which have been described above (supra para. 154), it should be noted that, during 18 years of investigations and proceedings, only six members of the “Los Masetos” paramilitary group, one leader of the ACDEGAM paramilitary group and one soldier (who was a sergeant) have been convicted. Despite the fact that this soldier was identified as a collaborator with the “Los Masetos” paramilitary group, he was only sentenced to one year’s detention for concealment with regard to information regarding paramilitary member Julián Jaimes. 145 Cf. Case of Gómez-Palomino, supra note 119, para. 80; and Case of the Serrano Cruz Sisters. Judgment of March 1, 2005. Series C No. 120, para. 83. 146 Cf. Case of La Cantuta, supra note 8, para. 157; Case of Goiburú et al., supra note 11, para. 84; and Case of Almonacid Arellano et al., supra note 16, para. 99 and 111. 147 Cf. Case of the Serrano Cruz Sisters, supra note 145, para. 88 and 105.