11 42. The National Code of Criminal Procedure, Law 23,984 of September 4, 1991, was in force at the time of the events that transpired in the autonomous city of Buenos Aires. In articles 456 to 489, that code regulates the cassation motions, constitutionality challenges, complaint motions and appeals for review. Inasmuch as the first three of these remedies were used with respect to some of the alleged victims, the pertinent provisions of those articles are transcribed below. 43. In the case of the cassation motion, Article 456 of the National Code of Criminal Procedure sets out the circumstances under which cassation is the proper remedy, as follows: The cassation motion may be filed for the following causes: 1) Failure to observe or correctly apply the substantive law. 2) Failure to observe the provisions that this Code sets forth, on pain of inadmissibility, lapsing of legal action or nullity, provided the petitioner –save in cases of absolute nullity- has demanded, within the prescribed period of time, that the error be corrected, if correction is possible, or has entered an objection for cassation. 44. As for the procedure through which a cassation motion is to be filed, Article 463 of the National Code of Criminal Procedure provides that: The cassation motion shall be filed with the court that delivered the ruling, within ten (10) days of notification and by means of a brief signed by a barrister setting forth the specific legal provisions deemed to have been violated or erroneously applied and spelling out how the petitioner would have the law applied. Each cause must be set forth separately. This is the petition of last resort and once filed no other petition may be brought. 45. Article 467 of the National Code of Criminal Procedure reads as follows: The parties must be represented by a barrister. When a remedy has been filed by another party and the accused does not appear for court or is unrepresented, the president of the court will name a court-appointed attorney to represent the accused. 46. As for what transpires when the motion is admitted, Articles 470 to 473 of the National Code of Criminal Procedure provide for a number of possibilities depending on whether a violation of substantive law was found (Article 470), a violation of procedural rules was shown (Article 471), or the legal errors had no impact on the decision (Article 472). Those provisions read as follows: Art. 470. – If the ruling being challenged has failed to observe the substantive law or misapplied it, the tribunal shall void the ruling and decide the case in accordance with the law and the precedents that it cites. Art. 471. – In a case in which procedural rules have not been observed, the tribunal shall nullify the proceedings and remit the case to the appropriate tribunal to retry the case. Art. 472. – Errors of law in the court’s explanation of the ruling being challenged that have not impacted the ultimate decision shall not have the effect of nullifying the decision, but must be corrected, as must any material errors in the determination or computation of sentence. 47. As for the remedy challenging the constitutionality of a ruling, the pertinent part of Article 474 provides that the constitutionality challenge is permissible in the case of final rulings (…) if there has been any question as to the constitutionality of a law, ordinance, decree or rule that regulates a matter governed by the Constitution, and the ruling or the order of the court is not in the petitioner’s favor. 48. Under Article 476 of the National Code of Criminal Procedure, the complaint motion is admissible in the following case: When an appeal that can be filed with another court is denied, the petitioner may immediately file a complaint motion seeking a finding to the effect that the original appeal was improperly denied.