49 impact that said decision would have on the development of the investigation conducted in Peru for the case of Mr. Anzualdo. 150. The Court deems appropriate to recall that, in the terms of the obligation to investigate, Peru must ensure the effective identification, investigation, prosecution and, if applicable, punishment of all the perpetrators and instigators of the forced disappearance of Mr. Anzualdo Castro; to such end, it shall not resort to the application of legal concepts that threaten the pertinent international obligations. 151. Finally, the representatives pointed out that no action has been carried out in any of the investigations in order to shed light on the whereabouts of Mr. Anzualdo Castro or in order to locate his mortal remains. Therefore, based on the report of the expert witness Baraybar, the representatives emphasized the negligence of the authorities in not conducting a DNA testing on the remnants of bones found in the incinerators of the basements of the SIE and they also highlighted the fact that it is unknown who is in charge of taking care of such remains at present. In addition, the State presented, in the final argument, a directive that regulates the investigation conducted by the prosecuting authority as a result of the finding of human remains related to grave human rights violations196. 152. This Court notes that the investigations initiated since the year 2002 are based on new information that indicates that Mr. Anzualdo was taken to the basements of SIE. However, from the information available regarding the existence of incinerators and human bone remains of said office197, it does not spring that the investigating authorities have adopted measures to compare the remains found with the DNA of the relatives of the people that could have been in said basements198. 153. In short, even though the State has conducted important investigations to get to the bottom of the complex structure of the people involved in the planning and execution of grave human rights violations committed during the internal conflict of Peru, these investigations have not been oriented until recently and within certain limitations, to the determination of the participation of said structures in the forced disappearance of Mr. Anzualdo Castro. 154. To conclude, the principle of due diligence required that the proceedings be carried out taking into account the complexity of the facts, the context in which they 196 Internal directive of the Public Prosecutor’s Office Nº 011-2001-MP-FN of September 8, 2001 (Record of evidence, volume XIII, appendix to the final arguments of the State, pages 4526 to 4531). 197 On August 25, 2004 a criminal expert assessment, related to the inspection and taking of sample to determine the elements incinerated in the Second Basement (Almacén de recuperacion ingenieria Warehouse of engineering recovery) of the Army's Intelligence Service, was forwarded to the Office of the Investigating Magistrate of the Special Criminal Chamber of the Supreme Court of Justice. Said expert assessment reveals that it was determined, by means of a forensic anthropologic examination, that one of the samples taken on June 11, 2004 at the internal base of the incinerator of the second basement of the Intelligence Service corresponds to a human bone structure. Cf. Official letter Nº 4237-04-DIRCRIDIVLACRI-DEPING-PNO of August 19, 2004 (Record of evidence, volume VIII, Appendix 14 to the brief of pleadings and motions, pages 2831 to 2864). 198 The expert witness Baraybar emphasized, regarding the inspection conducted in the year 2004, that “the approach of the forensic investigation in cases of forced disappearance is very specific and different from the approach applied to normal criminal investigations, which is basically the best approach for this kind of examination, that is, to basically focus on the object; the object of the study, finally, is the recovered object and not the context; but, no samples of the relatives were taken; no DNA was processed; no inspections were conducted in the area where the remains could be located; no universe of probable victims was determined; there are many levels, let say, together, but time is the enemy.” Expert opinion rendered by expert witness José Pablo Baraybar Do Carmo at the public hearing held before the Inter-American Court on April 2, 2009.