35 ensure that this is compatible with Article 7(3) of the American Convention, it must be based on the need to ensure that the detainee will not impede the efficient conduct of the investigations or evade justice,135 and that it be proportional. Likewise, when a request is received for the release of those detained, the judge must explain the grounds, even if very briefly, on which he considers that preventive detention should continue. 136 Despite this, even when there are reasons for keeping a person in pretrial detention, the length of time should not exceed reasonable limits as established in Article 7(5) of the Convention. 137 123. Moreover, although the Commission in the Merits Report for this case spoke in general terms about violation of article 7 of the Convention, without specifying or declaring violation of Article 7(3), it did note in its final written observations that the arbitrary nature of pretrial imprisonment persisted even after the ratification of the Convention despite the State’s duty to put a stop to this type of arbitrary action (supra par. 99). Representatives Vega and Sommer offered similar views in a section of their pleadings (supra par. 102). 124. The Inter-American Defenders asserted that the applicants had petitioned for release but received decisions of denial (supra par. 106). However, they offered no evidence in this regard dated after September 5, 1984. Mr. Óbolo received release orders on March 31, 1987 (supra par. 78), and Mr. Cardozo, on July 23, 1987 (supra par. 79), in both cases because they had lodged a writ of “queja” and received a response,138 and these were the petitions that finally led the Supreme Council of the Armed Forces to issue Decision 429/87, releasing the remaining applicants on August 11, 1987.139 125. Notwithstanding these events, the Court notes that during the period from September 5, 1984 to the months of March (for Mr. Óbolo), July (for Mr. Cardozo) and August (for the others), 1987, the case file shows no evidence that the authorities conducted any review of the pretrial detention of applicants still being held, indicating no verification as to whether sufficient grounds remained to prolong the pretrial detention, that is, whether the accused might have impeded the development of the proceedings or evaded the action of justice. 126. The State argued, in this regard, that the review performed by the National Appeals Chamber and subsequently by the Supreme Council of the Armed Forces in 1987 demonstrates that the State did in fact review the pretrial detention of the alleged victims (supra par. 111). This argument by the State, it is worth noting, suggests that there had been no previous review by a judge during the period under study. 127. The State later asserted before the Inter-American Court that the pretrial detention was justified by the flight of Mr. Galluzzi and the requests for an order of self-amnesty by the applicants (supra par. 111), although the case file contains no evidence of a domestic judicial decision on the matter. The Court therefore dismisses these arguments in view of the fact that potential risk to the proceedings is not to be presumed, but must be verified based on 135 Cfr. Case of Bayarri v. Argentina, par. 74; Case of Norín Catrimán et al. (Leaders, Members and Activist of the Mapuche Indigenous People) v. Chile, par. 311. 136 Cfr. Case of Chaparro Álvarez and Lapo Íñiguez v. Ecuador, par. 117. 137 Cfr. Case of Bayarri v. Argentina, par. 74. 138 Cfr. Decision by the National Appeals Chamber, July 23, 1987, and Decision by the Supreme Council of the Armed Forces, August 11, 1987 (evidence file, folios 7978 and 7979, and 8054 to 8058). 139 7979). Cfr. Decision by the Supreme Council of the Armed Forces, August 11, 1987 (evidence file, folios 7978 and