38 122. The Commission observes that Decree No. 117-2003, which amended Article 332 of the Penal Code, expressly provides that maras will henceforth be classified as unlawful associations, and that mere membership in these youth gangs would be a crime. However, the law that criminalizes membership in the so-called “maras” does not define the distinctive features that define a person’s membership in any of these groups. In other words, the law does not clearly define what elements are regarded as punishable offenses. This ambiguity in the anti-gang law meant that in practice that determination was made arbitrarily and at the discretion of the authorities charged with enforcing that law. Therefore, the Commission deems that the norm in question opened up a margin of discretion that was so broad that it allowed many people to be arbitrarily detained merely on basis of the perception that they belonged to a gang, without considering other factors such as whether the individual in question is an active criminal, a former member of one of these groups, some who wears the tattoos of a certain gang but is not involved in any criminal activity at the time he or she is taken into custody. 123. The Inter-American Commission considers that Decree No. 117-2003 did not establish the mechanisms or criteria by which to verify whether there was any illicit conduct. It therefore does not comply with a requirement that is part of any democratic system, which is to take the precautions necessary to ensure that punitive power is exercised with absolute respect for fundamental rights. Therefore, that amendment to the Penal Code does not comply with the principle of freedom from ex post facto laws established in Article 9 of the American Convention. 124. Therefore, the Inter-American Commission deems that inasmuch as Decree No. 1172003 lacks objective enforcement criteria and does not comply with the standards established in Article 9 of the American Convention, one can conclude that the detentions and arrests made on the grounds of that law, following the patterns described in the preceding paragraphs, were arbitrary in the sense of Article 7(3) of the American Convention. 125. Based on the above considerations, the Inter-American Commission finds that the State violated articles 9 and 7(3) of the American Convention, in conjunction with the obligations to respect and ensure established in articles 1(1) and 2 thereof, to the detriment to the 22 fire victims named in paragraph of 116 of the present report. D. Right to a fair trial and right to judicial protection (articles 8 and 25 of the American Convention, in conjunction with Article 1(1) thereof) 126. Article 8(1) of the Convention reads as follows: Every person has the right to a hearing, with due guarantees and within a reasonable time, by a competent, independent, and impartial tribunal, previously established by law, in the substantiation of any accusation of a criminal nature made against him or for the determination of his rights and obligations of a civil, labor, fiscal, or any other nature. 127. Article 25(1) of the Convention provides that: Everyone has the right to simple and prompt recourse, or any other effective recourse, to a competent court or tribunal for protection against acts that violate his fundamental rights recognized by the constitution or laws of the state concerned or by this Convention, even though such violation may have been committed by persons acting in the course of their official duties. 128. The obligation of the States Parties to the American Convention to "ensure" the free and full exercise of the rights recognized by the Convention to every person subject to their jurisdiction (Article 1(1)) implies that States Parties have a duty to prevent, but also a duty to investigate and punish any violation of the rights recognized by the Convention, to restore the