19 when comparing the bullet heads, a test one and the other related to the case of Anstraum Aman Villagrán Morales, the expert had determined that both bullet heads were fired by the same gun. He added that when a policeman is off-duty he must leave his arm in the armory, where the date, name and signature of the person who hands over the equipment are recorded in a ledger. He also investigated another case of the murder of a “street child”, Nahamán Carmona López, committed by agents of the National Police Force, which occurred in 1994. He added that police agents had been responsible for other cases of the abuse and murder of “street children”. i. Testimony of Ayende Anselmo Ardiano Paz, National Police Force investigator He declared that he drew up a report on his investigation into the murder of Anstraum Aman Villagrán Morales. He took part in the inspection of the site where this occurred. He interviewed Julia Griselda Ramírez López, who told him that, on the day of his death, Villagrán Morales had been in the “PepsiCola” kiosk, where she worked. Villagrán Morales encountered Rosa Trinidad Morales Pérez there and she threatened him, saying that “he should leave the place because, to the contrary, the same thing would happen to him as had happened to his companions”. He said that he conducted the procedure for the photographic identification of the policemen, Samuel Rocael Valdez Zúñiga and Néstor Fonseca López, when Griselda Ramírez López identified the aforementioned agents. Furthermore, he interviewed the mother of Mrs. Ramírez López, Julia Consuelo López de Ramírez, who told him that she had received death threats from Samuel Rocael Valdez Zúñiga and Néstor Fonseca López; no one ordered an investigation of this fact. He indicated that, according to the ballistic test, the bullet head found near the body of Anstraum Aman Villagrán Morales coincided with fragments in Samuel Rocael Valdez Zúñiga’s revolver. In his report, he concluded that Néstor Fonseca López and Samuel Rocael Valdez Zúñiga were responsible for the murder of Anstraum Aman Villagrán Morales “because of the interviews and the certainty of the persons that [he] interviewed and also because of the ballistic test on the arm that [Samuel Rocael Valdez Zúñiga] carried, since there were sufficient elements to be sure that he was responsible”. In his report, he added that Rosa Trinidad Morales Pérez was also a possible suspect of the death of Villagrán Morales, because “she did not get on well with [the] children”. He indicated that he was only summoned by a judge when arrest warrants against the two alleged perpetrators were issued and when the police report was delivered. He declared that it is not the normal practice in Guatemala that the officer in charge of an investigation does not appear in court to be questioned. C) EXPERT WITNESS EVIDENCE 66. The Court heard the reports of the expert witnesses that are summarized below in a public hearing: a. Report of Roberto Carlos Bux, Deputy Director of the Bay County Forensic Center, San Antonio, Texas