44 DAS replied that they did not. 236 On September 3, 1999, the UNDH requested information on several different generals, majors and sergeants of the FTA.237 140. On May 2, 2000, the UNDH issued a decision to open an investigation into the disappearances of Aníbal de Jesús Castaño Gallego, Óscar Hemel Zuluaga Marulanda, Juan Crisóstomo Cardona Quintero, Miguel Ancízar Cardona Quintero, María Irene Gallego Hernández, Juan Carlos Gallego Hernández, Jaime Alonso Mejía Quintero, Hernando de Jesús Castaño Castaño, Andrés Suárez Cordero, Octavio de Jesús Gallego Hernández and Orlando de Jesús Muños Castaño. This decision indicated that evidence points to “paramilitary groups allegedly sponsored by members of the military forces who were operating in that area of the country.” Ramón Isaza, leader of the Self-Defense Forces of Magdalena Medio and Major Carlos Guzmán Lombana were also implicated in the investigation. Requests were also made to: i) conduct on-site judicial inspections in order to obtain information on the FTA; and ii) identify and locate the members of the military who were stationed at La Piñuela military base in June and July 1996.238 141. In May and June 2000, Major Carlos Guzmán was summoned to provide an initial statement on the facts in response to the charges239 but he failed to appear. On May 9, 2000, the UNDH requested an arrest warrant for Ramón Isaza240 which could not be done effectively.241 142. On August 15, 2000, the UNDH granted the motion of the family members of the victims to become a civil party to the proceedings.242 143. On August 23, 2000 investigators of the Office of the Prosecutor issued an official letter concluding that the FTA “had jurisdiction over the Medellín-Bogotá highway at the time of the events.” They also reported that with regard to the alleged victims in the domestic process, “the inquiries have pointed to paramilitary groups allegedly sponsored by members of the military forces who were 236 Annex 10. Official Letter No. 046/DAS.ANT.CI from the DAS, dated January 21, 1999. Case File No. 233 UNDH. Book No. 3A. Folio 2. Compact disk attached to petitioners’ communication of June 24, 2010. 237 Annex 10. Official Letter from the Special Prosecutor of the Human Rights Unit, dated September 3, 1999. Case File No. 233 UNDH. Book No. 3A. Folio 61. Compact disk attached to petitioners’ communication of June 24, 2010. 238 Annex 10. Decision of the National Human Rights Unit of the Office of the Attorney General of the Nation to open investigation, dated May 2, 2000. Case File No. 233 UNDH. Book No. 3A. Pages 79-87. Compact disk attached to petitioners’ communication of June 24, 2010. 239 Annex 10. Clerk’s Report of the National Human Rights Unit, signed by Judicial Clerk Esperanza Uribe, dated May 8, 2000. Case File No. 233 UNDH. Book No. 3A. Page 88. Compact disk attached to petitioners’ communication of June 24, 2010. 240 Annex 57. Arrest warrant No. 093 from Judicial Investigator II, Aura Navia Zúñiga, of the National Human Rights Unit of the Office of the Attorney General of the Nation, dated May 9, 2000. Annex to petitioners’ submission received in the IACHR on February 1, 2007. 241 Annex 10. Official Notice No. 158 of the National Human Rights Unit of the Office of the Attorney General of the Republic, dated June 23, 2000. Case File No. 233 UNDH. Book No. 3A. Page 111. Compact disk attached to petitioners’ communication of June 24, 2010. 242 Annex 10. Decision of the National Human Rights Unit of the Office of the Attorney General of the Republic, dated August 15, 2000. Case File No. 233 UNDH. Book No. 3A. Pages 132-134. Compact disk attached to petitioners’ communication of June 24, 2010.