14 means that the Court was to investigate the facts in order to ascertain the evidence of Colombia’s responsibility. In its brief of response, the Commission stated that the circumstances of Mr. Hernán Lizcano Jacanamejoy’s death were unclear, which meant that the question of Colombia’s responsibility with respect to Article 4 of the Convention was also unclear. Here, the Commission’s position begins to change, and it now implies that Colombia would have to prove that it was not responsible. The Commission’s position was spelled out at the public hearing on the merits, held on May 28, 2001. Its contention is that here, because of “the particular circumstances of the case” and “from the very special angle of international human rights law,“ the burden of proof should be reversed. The Commission does not explain what “the particular circumstances of the case” might be nor does it explain that “special angle of international human rights law.” El onus probandi is not up to the court’s discretion; instead, it is dictated by the rules of law in force. The Commission has not cited any treaty in support of its argument, nor has it tried to show the existence of some general or specific rule or custom of international law on the subject. In some cases, a court may have to determine how strong the evidence must be to constitute proof of facts. In the instant case, to prove Colombia’s responsibility, it must be shown that State agents executed Hernán Lizcano Jacanamejoy. 42. b) that because transpired, it its final brief, The second line of argument the Commission pursued was to assert the State had not conducted a serious investigation of the events that had to assume responsibility for the death of Lizcano Jacanamejoy. In the Commission states the following in this regard: The State’s omissions in this respect are violations of the victim’s right to life by reason of the failure to conduct a serious investigation. Prior to this, at the public hearing, the Commission had stated the following: Responsibility for the violation of the right to life is also established by the failure to guarantee protection of this right. The Commission considers that the very fact that there was never the kind of thorough, effective and impartial investigation of the facts that various articles of the American Convention require, is a violation of the State’s affirmative obligation to ensure and protect the right to life. This is because the protection of this right does not end upon a person’s death and is more than the obligation to respect the right to life. The State must also provide an ex post facto procedure to establish that the facts surrounding a murder perpetrated by its agents were not acts committed by those agents. While in some cases, the failure to investigate may be construed as an attempt to protect the authors of the crime of murder,4 this reasoning cannot be postulated as a generic rule applicable across the board. Apart from the question of the legitimacy of a rule such as the one postulated by the Commission, the fact is that it would be applicable only if no serious investigation had been conducted. In the instant case, the argument that no serious investigation was conducted cannot be made. There 4 Bámaca Velásquez Case, Judgment of November 25, 2000. Series C No. 70, paragraphs 191, 194 and 200; Durand and Ugarte Case, Judgment of August 16, 2000. Series C No. 68, paragraphs 122 and 130, and Villagrán Morales et al. Case (The “Street Children” Case), Judgment of November 19, 1999. Series C No. 63, paragraphs 228, 230, 233 and 237.