168. Lastly, TOF 3 held that it was not credible that “experienced investigation officials, instead of requesting a search warrant in order to seize the elements that could shed light on the investigation or the measures of personal restraint, remained inactive […] in a role of babysitters for the children of the main suspect” 150 . Consequently, TOF 3 declared the nullity of the raid carried out on the building on 107 República street. - The Commission’s Considerations 169. The Commission highlights - in line with what was warned by the Federal Oral Criminal Court No. 3 and by Chamber II of the National Chamber of Criminal Cassation in their judgments dated October 29, 2004 and May 19, 2006151- that certain judicial and police officials in charge of coordinating the investigation of the attack who were present at the scene of the attack did not adequately fulfill their duties to protect the scene of the incident, collect in an adequate and timely manner the evidence found there, and ensure their chain of custody. 170. The Commission recognizes that the magnitude of this criminal act, both in terms of the degree of destruction caused by the explosion as well as the number of fatalities and injuries, which determined that, during the first hours, the priority was concentrated on the tasks debris removal and search for survivors. In this regard, the Commission takes into consideration the difficulty of carrying out the tasks of gathering evidence in the context of events of this nature. 171. However, the Commission finds that, in light of the principle of due diligence, the actions of those officials who failed to accurately document the circumstances in which various elements of great relevance to the investigation were found, in particular the engine parts of the Renault Trafic van, are not justifiable. As indicated at the time by the TOF 3, the police did not show a "minimum concern" to receive the statement of those who witnessed the discovery of said pieces or to carry out a reconstruction or observation of the place where they were found. Consequently, the Commission finds no grounds in the drafting of the record of the seizure, based on the statements of persons on whom there is no effective evidence that they were present at the time of said discovery. 172. In connection to this point, the Commission recalls that, in the face of a violent death, the Inter-American Court has indicated that “the correct handling of the crime scene is a starting point for the investigation and, therefore, a determining factor to clarify the nature, circumstances, and characteristics of the crime, as well as the participants in the act”152 and that, according to international standards on the matter, “investigators must, as a minimum, photograph said scene, any other physical evidence […] and make a report detailing any observations of the scene, the actions of the investigators, and the disposition of all the collected evidence”153. 173. On the other hand, the Commission understands that the procedure carried out by agents of the SIDE and the DPOC at Carlos Telleldín's home on July 26 and 27 also implied a lack of due diligence in the practice of Annex 2. Judgment of the TOF 3. Chapter IX, page 3736 and 3737. Annex 1 to the petitioner’s communication dated November 11, 2019. Annex 2. Judgment of the TOF 3. Chapter IX, page 2696. Annex 1 to the petitioner’s communication dated November 11, 2019; Annex 3. Judgment of Chamber II of the National Chamber of Criminal Cassation dated May 19, 2006, pp. 271 to 277. Annex 7 to the petitioner's communication dated November 11, 2019. 152 I/A Court H.R., Case of Velásquez Paiz et al. v. Guatemala. Preliminary Objections, Merits, Reparations and Costs. Judgment of November 19, 2015. Series C No. 307, para. 152; I/A Court H.R., Case of the “Street Children” (Villagrán Morales et al.) v. Guatemala. Merits. Judgment of November 19, 1999. Series C No. 63, paras. 231 to 233. 153 I/A Court H.R., Case of González et al. (“Cotton Field”) v. Mexico. Preliminary Objection, Merits, Reparations and Costs. Judgment of November 16, 2009. Series C No. 205., para. 305. See also: UN. Office of the United Nations High Commissioner for Human Rights. Minnesota Protocol on the Investigation of Potentially Unlawful Death (2016), para. 65: “Every stage of evidence recovery, storage, transportation and forensic analysis, from crime scene to court and through to the end of the judicial processes, should be effectively recorded to ensure the integrity of the evidence. This is often referred to as the “chain of evidence” or “chain of custody”. Chain of custody is a legal, evidentiary concept requiring that any prospective item of evidence be conclusively documented in order to be eligible for admission as evidence in a legal proceeding. This includes the identity and sequence of all persons who possessed that item from the time of its acquisition by officials to its presentation in court. Any gaps in that chain of possession or custody can prevent the introduction of the item as evidence against a criminal defendant. Evidential material should be transported in a manner that protects it from manipulation, degradation and crosscontamination with other evidence. Each piece of evidence recovered, including human remains, should be uniquely referenced and marked to ensure its identification from point of seizure to analysis and storage. To meet chain of evidence and integrity requirements, the transportation, tracking and storage of this evidence should include the investigator’s details”. 150 151 34