- 52 - Criminal Cassation Chamber decided not to review the judgment, which then became final.206 146. Regarding the arguments of the Commission, the representatives, and the State concerning the remedy of cassation and the book with Mr. Castaño Gil’s declarations, the Court considers that, on this point, the issue in dispute is not based on the possibility or pertinence of admitting evidence during the cassation remedy, but rather on the existence of a well-known fact, which has already been examined above. Therefore the Court finds it unnecessary to analyze the State’s defense arguments concerning the remedy of cassation. 147. Furthermore, the Attorney General’s office indicated that this type of crime is complex to deal with; hence the intention should be “to include the heads of these organizations as authors,” and not merely the perpetrators, because the latter may be fungible for the purposes of the crime. In this regard, he stated that “[i]t is this fungibility of the perpetrator that results in the head of the organization retaining ownership of the act rather than transferring it to the individual who executes the act, because, whatever happens, the punishable act is perpetrated, even if the individual originally chosen to commit the crime reneges.”207 Hence, the Court considers that the death of some of the presumed authors should not halt the investigations; rather it should indicate to the authorities the lines they should follow to find the leaders of the structures. 148. Additionally, it was alleged that a key witness in case, Elcías Muñoz (supra para. 106), was the victim of threats, and that his common-law wife and daughter were disappeared in February 1997.208 It has also been proved that some of the victim’s next of kin who testified in the proceedings before the Court and who took part in the search to obtain justice, stated that they had been threatened and harassed at the time of the facts and also during the domestic investigations (infra paras. 184 to 195). 149. As indicated above (supra paras. 116 to 122), due diligence in the investigations involved taking into account the patterns of action of the complex structure of the individuals who perpetrated the extrajudicial execution, because the structure remains after a crime has been committed; and, precisely to ensure its impunity, it uses threats to instill fear in those who investigate the crime and in those who could be witnesses or have an interest in the search for the truth, as in the case of the victim’s next of kin. The State should have adopted sufficient measures of protection and investigation to prevent that type of intimidation and threat. 150. Even though the Court cannot substitute the domestic authorities in determining the punishment for the crimes established by domestic law, and has no intention of 206 Cf. Judgment handed down on November 10, 2004, by the Criminal Cassation Chamber of the Supreme Court of Justice in Investigation No. 18,428, supra note 163, folios 1868 to 1937. No evidence was provided with regard to the affirmations concerning the Civil Cassation Chamber; nevertheless, the State accepted this paragraph in its entirety in the brief in answer to the application (merits file, tome III, folio 840). 207 Opinion issued by the office of the Attorney General of the Nation on the legality of the second instance judgment in relation to Investigation No. 18,428, supra note 101, folios 1841 and 1845. 208 Cf. testimony given by Elcías Muñoz Vargas before the Regional Court of Santafé de Bogotá in proceedings No. JR 5393 on January 29, 1999, supra note 148, folio 4174; opinion provided before notary public (affidavit) by expert witness Carlos Martín Beristain on November 27, 2009 (evidence file, tome XX, folio 8243); judgment delivered by the Third Criminal Court of the Santafé de Bogotá Specialized Circuit in Investigation No. 5393-3 on December 16, 1999, supra note 75, folios 1684 to 1685, and judgment handed down on November 10, 2004, by the Criminal Cassation Chamber of the Supreme Court of Justice in Investigation No. 18,428, supra note 163, folios 1877 to 1878.