38 136. In this regard, the Court observes that in light of Article 144 of the Constitution,134 the civil police were exclusively responsible for investigating the criminal acts referred to in the interception application owing to their ordinary nature. Hence, the only police authorities legally empowered to request the interception of the COANA and ADECON telephone lines were the chief of police responsible for the investigation or the Secretary for Security in substitution of the former. In the instant case, even though the former Secretary, Cândido Martins, endorsed the application made by Colonel Kretschmer, the application and its authorization were placed in the case file of the monitoring petition after the measure had ended, together with the police report on the delivery of the recorded tapes. Consequently, the Loanda Court did not make a ruling in this regard. To the contrary, Judge Khater issued her authorizations based on the requests submitted by Major Neves and by Sergeant Silva, both members of the Military Police, and merely noted on the applications that she had examined the requests and granted them (supra paras. 91 and 92). 137. Furthermore, even though the judge was empowered to order the telephone interception ex officio, her decisions stated that when ordering it, Judge Khater acted authorizing the requests of the military police agents and not on her own initiative, without respecting Article 3 of Law No. 9,296/96. Justification of the telephone interception order and maximum duration of the procedure – Article 5 of Law No. 9,296/96135 138. Article 5 of Law No. 9,296/96 establishes that the decision authorizing a telephone interception shall be founded (to the contrary it will be null) and shall also indicate how the procedure is to be carried out. 139. On previous occasions, when examining judicial guarantees, the Court has emphasized that decisions adopted by domestic bodies that could affect human rights must be duly founded and justified; otherwise such decisions would be arbitrary.136 Using rational arguments, the decisions should explain the grounds on which they were based, taking into consideration the arguments and the body of evidence provided to the proceedings. The obligation to state the reasons for the decision does not require a detailed response to every argument included in the application, but may vary according to the nature of the decision. In each case, it is necessary to assess whether this guarantee has been satisfied.137 In proceedings whose juridical nature requires the decision to be issued without 134 Constitution of the Federative Republic of Brazil, supra note 115, folio 4039. Article 144. Public security, which is an obligation of the State, and the right and responsibility of all, is exercised for the preservation of public order and the security of people and property, by the following entities: […] § 4. The civil police, headed by career police chiefs, are responsible, with the exception of the jurisdiction of the Union, for the functions of the judicial police and the clarification of criminal offenses, except offenses by the military; […] § 5. The military police are responsible for the “ostensiva” [Note: observable as opposed to secret] police and for the preservation of public order; […] 135 Law No. 9,296 of July 24, 1996, supra note 128, folio 55. Article 5. The decision shall be founded, or to the contrary it will be null; it shall also indicate the means of executing the procedure, which may not exceed 15 days, renewable for the same duration provided that its essential nature as a means of evidence has been verified. 136 Cf. Case of Yatama, supra note 16, para. 152; Apitz Barbera et al. (“First Administrative Court”) v. Venezuela, Preliminary objection, merits, reparations and costs.. Judgment of August 5, 2008, Series C No. 182, para. 78, and Case of Tristán Donoso, supra note 9, para. 153. 137 Cf. Case of Apitz Barbera et al. (“First Administrative Court”), supra note 136, para. 90 and Case of Tristán Donoso, supra note 9, para. 153.