290. In particular, amnesty laws violate the State’s international obligation to investigate and punish serious human rights violations by preventing the victims’ next of kin from being heard by a judge, in accordance with the provisions of Article 8(1) of the American Convention. In addition, they violate the right to judicial protection established in Article 25 of this instrument precisely due to the failure to investigate, pursue, capture, prosecute and punish the perpetrators of such acts, which results in non-compliance with Article 1(1) of the Convention. 291. In light of the general obligations established in Articles 1(1) and 2 of the American Convention, the States Parties have the obligation to take every possible measure to ensure that no one is denied judicial protection and the exercise of the right to a simple and effective remedy in the term of Articles 8 and 25 of the Convention. Moreover, once it has ratified the American Convention, pursuant to its Article 2, the State must take all necessary measures to derogate any legal provisions that could contravene the Convention, such as those that prevent the investigation of serious human rights violations, because these leave the victims defenseless and result in the perpetuation of impunity; furthermore, they prevent the victims and their next of kin from knowing the truth. 292. That said, it is evident that, from the moment it was promulgated, the Brazilian Amnesty Law referred to crimes committed in a situation where there was no non-international armed conflict, and it has no legal force because it prevents the investigation and punishment of serious violations of human rights and represents an obstacle for the investigation of the facts of this case and the punishment of those responsible. The Court considers that the said law cannot have legal force in this case, and its application by the domestic courts cannot be considered valid. In 1992, when the American Convention was in full force for Brazil, the judges who intervened in the application for habeas corpus should have conducted a “control of conventionality” ex officio between domestic law and the American Convention; evidently in accordance with their respective competence and the corresponding procedural rules. And these considerations apply to the case sub judice even more clearly since the conducts involved reached the threshold of crimes against humanity. 293. Finally, the Court shares the opinion of the International Law Commission that an amnesty adopted by a State would not prevent prosecution by another State with concurrent competence to try the crime. 324 In the State that granted the amnesty, its validity would have to be examined, inter alia, in light of that State’s obligations under the principles of general international law mentioned in this judgment and, specifically, the obligations contracted when ratifying the American Convention on Human Rights and sovereignly accepting the contentious jurisdiction of this Court. 294. Accordingly, the Court finds that, in situations that involve crimes under international law or crimes against humanity, States are authorized to use the principle of universal jurisdiction in order to comply with the obligation to investigate, prosecute and punish those responsible and with the obligations towards the victims and other persons. iv) Universal jurisdiction 295. The obligation to establish and implement the system of justice in cases of human rights violations falls, fundamentally, to the State where the violations occur. In the case of crimes against humanity, this obligation remains unchanged, because the responsibility to be accountable to society for such conducts belongs, above all, to the responsible State. However, based on the nature and gravity of crimes against humanity, this obligation transcends the 324 See, for example, ECHR. Ould Dah v. France, No. 13113/03, Admissibility decision of March 17, 2009. 75