47 Effective Investigation of Extrajudicial, Arbitrary, and Summary Killings of the United Nations must be taken into account in orienting said proceedings.83 The state authorities that carry out an investigation must, inter alia, a) identify the victim; b) recover and preserve the evidentiary material related to the death; c) identify possible witnesses and obtain their statements with regard to the death that is being investigated; d) determine the cause, form, place, and time of death, as well as any procedure or practice that could have caused it, and e) distinguish between a natural death, an accidental death, suicide, and homicide. Besides, it is necessary to thoroughly investigate the crime scene, autopsies and competent professionals employing the most appropriate procedures must carefully practice analysis of the human remains. 121. The Court observes that in the case sub judice several proceedings were performed, but they presented important omissions, such as: a) the removal of the victims’ bodies was done on September 17, 1995, without assuring the recollection and preservation of the crime scene. Blood samples of the victims were not taken, nor were their clothes examined. There is no evidence that the crime scene was analyzed for the presence of blood, hairs, or fibers or any type of fingerprints, nor were the bodies or objects examined to determine the existence of fingerprints. In the photographs of the bodies in the case file the existence of wounds or torture markings cannot be appreciated, and in some of the cases the photographs are only of the top part of the body. This becomes more serious in two of the proceedings regarding the removal of the bodies of Marco Antonio Servellón García and Diomenes Obed García, since the record indicates that photographs of the bodies were not taken due to lack of film for the camera; b) in the case of Orlando Álvarez Ríos the body appeared with signs of having been the object of sexual violence by the aggressors, however, no exam was run to prove it. The Public Prosecutor’s Office in charge of the investigation did not request proceedings in this sense, and c) the autopsies of Marco Antonio Servellón García, Rony Alexis Betancourth Vázquez, Diomedes Obed García Sánchez, and Orlando Álvarez Ríos were included in the criminal proceedings before the First Criminal Court on June 7 and August 5, 1996. In said autopsies the cause of death of each of the victims was stated and the existence of wounds produced with fire weapons or cutting and thrusting weapons was mentioned, but they did not refer to other types of wounds or torture markings or physical violence in the bodies. 122. In what refers to other marks or injuries in the victims’ bodies, in the report of claim No. 9173, issued by the Main Prosecutor of the Human Rights Public Prosecutors’ Office on September 17, 1995, it indicated that “all [the bodies] had signs of torture.” Despite the conclusion of said report, the prosecutors’ office in charge did not request the performance of a new autopsy or of additional exams to investigate and document the torture practiced on the victims prior to their death. 83 Cfr. Case of Montero Aranguren et al., supra note 12, para. 140; Case of Ximenes Lopes, supra note 3, para. 179; Case of the Ituango Massacres, supra note 3, para. 298; and Manual on the Prevention and Effective Investigation of Extrajudicial, Arbitrary, and Summary Killings of the United Nations, E/ST/CSDHA/.12 (1991).