89. In addition, the Court has considered that pre-trial detention should be a precautionary rather than a punitive measure.112 It should be applied exceptionally and cannot be based on general or special preventive purposes, which could be attributed to the punishment. Consequently, the Court reiterates that the rule should be the liberty of the accused while his criminal responsibility is being decided (supra para. 83). 90. Therefore, the judicial authority must only impose measures of this nature when it has been verified that: (a) the purpose of the measures that restrict or deprive liberty is compatible with the Convention; (b) the measures adopted are appropriate to achieve the purpose sought; (c) the measures are necessary, in the sense that they are absolutely essential to achieve the desired purpose and that, among all possible measures that are equally appropriate to achieve the proposed objective, no other measure exists that is less harmful to the right involved, and (d) they are strictly proportionate, so that the sacrifice inherent in the restriction of the right to liberty is not exaggerated or excessive compared to the advantages obtained from the restriction and the achievement of the purpose sought.113 91. The Court has also considered that any order for restriction of liberty that does not contain a sufficient statement of reasons that permits an evaluation of whether it is in keeping with the aforementioned conditions will be arbitrary. 114 The judicial decision should substantiate and demonstrate – clearly stating the reasons – the existence of sufficient indications to prove the criminal conduct of the individual concerned. 115 This safeguards the presumption of innocence.116 Moreover, the personal characteristics of the suspect and the gravity of the offense he is accused of are not, in themselves, sufficient justification for pre-trial detention.117 92. According to case law, pre-trial or preventive detention should be subject to periodic review so that it does not continue when the reasons for its adoption no longer exist. The judge should assess whether the reasons for the measure remain, and the need for and proportionality of the detention; also, whether the reasonable time has been respected. If not, the judge must immediately order the release of the detainee. It is the responsibility of the domestic authorities to provide sufficient reasons to maintain the restriction of liberty, and those reasons must be based on the need to ensure that the detainee does not impede the efficient conduct of the investigations or evade the action of justice.118 93. One of the principles that limit pre-trial detention is the presumption of innocence contained in Article 8(2), according to which a person is considered innocent until his guilt has been proved. This guarantee reveals that the elements that prove the existence of the legitimate purposes for the preventive deprivation of liberty cannot be presumed; rather the judge must substantiate his decision on the real and objective circumstances of the specific case, which it is for the prosecutor to prove and not the accused who also must be able to exercise his right of defense and to be duly Cf. Case of Pollo Rivera et al. v. Peru. Merits, Reparations and costs. Judgment of October 21, 2016. Series C No. 319, para. 122, and Case of Carranza Alarcón v. Ecuador, supra, para. 67. 112 Cf. Case of Chaparro Álvarez and Lapo Íñiguez v. Ecuador, supra, para. 93, and Case of Romero Feris v. Argentina, supra, para. 98. 113 Cf. Case of García Asto and Ramírez Rojas v. Peru, supra, para. 128, and Case of Carranza Alarcón v. Ecuador, supra, para. 75. 114 Cf. Case of Herrera Espinoza et al. v. Ecuador. Preliminary objections, merits, reparations and costs. Judgment of September 1, 2016. Series C No. 316, para. 143, and Case of Romero Feris v. Argentina, supra, para. 110. 115 Cf. Case of Usón Ramírez v. Venezuela. Preliminary objection, merits, reparations and costs. Judgment of November 20, 2009. Series C No. 207, para. 144, and Case of Romero Feris v. Argentina, supra, para. 110. 116 Cf. Case of Bayarri v. Argentina. Preliminary objection, merits, reparations and costs. Judgment of October 30, 2008. Series C No. 187, para. 74, and Case of Carranza Alarcón v. Ecuador, supra, para. 65. 117 Cf. Case of Chaparro Álvarez and Lapo Íñiguez v. Ecuador, supra, para. 117, and Case of Carranza Alarcón v. Ecuador, supra, para. 83. 118 25