previously in this section, the Court finds that res judicata is not absolute. Also, it should be emphasized that the decision that closed the investigation was not an acquittal issued in accordance with the guarantees of due process. To the contrary, it was a decision on an application for habeas corpus taken by a court without jurisdiction, 294 based on a law (Law No. 6683/79) that, according to this Court, had no legal force. Furthermore, the decision in question did not respect the legal consequences of the obligation erga omnes to investigate, prosecute and punish the perpetrators of crimes against humanity. Consequently, it was a ruling that had no legal force and that that does not alter the legal considerations set forth in this judgment. 276. Additionally, the 2008 decision of the federal judge is not a credible decision resulting from a judicial proceeding respecting judicial guarantees that had the purpose of determining the truth of the facts and the identification of those responsible for the violations denounced. To the contrary, it was a procedural decision to close an investigation. Accordingly, the Court considers that the ne bis in idem principle is not applicable. Finally, the Court points out that a decision based on a law that has no legal force because it is incompatible with the Convention does not generate the legal certainty expected of the system of justice. iii) Amnesty laws 277. Some States have alleged amnesties or similar devices in order to obstruct the investigation and, when applicable, the punishment of those responsible for serious human rights violations. 295 This Court, the Inter-American Commission on Human Rights, the relevant United Nations bodies and other regional and universal human rights bodies have ruled on the incompatibility with international law and the international obligations of the States of amnesty laws in relation to serious human rights violations. 278. As already indicated, this Court has ruled on the incompatibility of amnesties with the American Convention in cases of serious human rights violations or crimes against humanity with regard to Peru (Barrios Altos and La Cantuta), Chile (Almonacid Arellano et al.), Brazil (Gomes Lund et al.), Uruguay (Gelman) and El Salvador (Massacres of El Mozote and neighboring places). 279. Under the inter-American human rights system, of which Brazil forms part by sovereign decision, numerous rulings have been made on the incompatibility of amnesty laws with the treaty-based obligations of States in the case of serious human rights violations. These rulings are even clearer when they refer to crimes under international law, because their seriousness and magnitude is evident. 280. In this regard, it is important to point out that, as this Court has established, 296 international humanitarian law justifies the enactment of amnesty laws 297 when hostilities 294 This was recognized by the Federal Public Prosecution Service and the federal jurisdiction in 2008. The Substitute Federal Judge of the First Federal Criminal and Sentencing Court. Decision No. 2008.61.81.013434-2, January 9, 2009, p. 9 (evidence file, folio 4573). 295 In this case, the Court refers generically to “amnisties” to refer to laws that, regardless of what they are called, pursue the same objective. Cf. Case of the Massacres of El Mozote and neighboring placesv. El Salvador. Merits, reparations and costs, para. 285. 296 Article 6(5) of Protocol II Additional to the 1949 Geneva Conventions established that: “At the end of hostilities, the authorities in power shall endeavour to grant the broadest possible amnesty to persons who have participated in the armed conflict, or those deprived of their liberty for reasons related to the armed conflict, whether they are interned or detained.” 297 71