44 The different categories of prisoners shall be kept in separate institutions or parts of institutions taking account of their sex, age, criminal record, the legal reason for their detention and the necessities of their treatment. Thus: […] (b) Untried prisoners shall be kept separate from convicted prisoners[.]200 145. In its General Comment No. 21 concerning humane treatment of persons deprived of liberty, 201 the Human Rights Committee indicated that the segregation of accused from convicted prisoners established in Article 10, paragraph 2(a) of the Covenant was “required in order to emphasize their status as unconvicted persons who at the same time enjoy the right to be presumed innocent as stated in Article 14, paragraph 2 [of the Covenant].” In addition, the Committee indicated that “[t]he reports of States parties should indicate how the separation of accused persons from convicted persons is effected and explain how the treatment of accused persons differs from that of convicted persons.” 146. This Court has considered that Article 5(4) of the American Convention imposes on the States the obligation to establish a classification system for prisoners in penitentiary centers, in order to guarantee that accused persons are separated from convicted persons, and receive treatment adapted to their status as unconvicted persons.202 These guarantees can be understood as a corollary of the right of the accused person to be presumed innocent, while he has not been found guilty in accordance with the law, which is stipulated in Article 8(2) of the Convention. The State must demonstrate the existence and functioning of a classification system that respects the guarantees established in Article 5(4) of the Convention, as well as the existence of exceptional circumstances, if it does not separate accused persons from convicted persons. 147. The Court considers that the separation of accused persons from convicted persons requires not only keeping them in different cells, but also that these cells be located in different sections within a detention center, or in different institutions if this is possible. 148. In the instant case, it has not been proved that there was a system for classifying prisoners, separating the accused from the convicted, in the National Penitentiary where Mr. Neptune was imprisoned from June 27, 2004, to March 10, 2005. The State did not dispute the allegations of the Commission and the representative in this regard. Regarding the detention conditions, the witness Ronald Saint-Jean stated that “[t]he detention center did not separate the convicted persons (approximately 4% of the prison population) from those who had not been charged or put on trial.”203 200 Standard Minimum Rules for the Treatment of Prisoners, adopted by the First United Nations Congress on the Prevention of Crime and the Treatment of Offenders, held at Geneva in 1955, and approved by the Economic and Social Council by its resolutions 663 C (XXIV) of 31 July 1957 and 2076 (LXII) of 13 May 1977, Rule 8. 201 Cf. United Nations, Human Rights Committee General Comment No. 21: Replaces general comment 9 concerning humane treatment of persons deprived of their liberty (Art. 10). 10 April 1992, para. 9. 202 In the case of Tibi, the Court concluded that the State was responsible for the violation of Article 5(4) due to failure to separate prisoners, because “there was no system for classifying the detainees in the penitentiary center where Mr. Tibi was imprisoned and, consequently, he had to live alongside convicted prisoners and was exposed to greater violence.” Likewise, the Court concluded that Article 5(4) had been violated in the case of López Álvarez, because “it had been proved that in the penitentiary centers where Alfredo López Álvarez was imprisoned, there was no system to classify detainees,” so that “for the more than six years and four months that he was deprived of liberty, he remained in the company of convicted prisoners, without the State having cited or proved the existence of exceptional circumstances. Cf. Tibi v. Ecuador. Preliminary objections, merits, reparations and costs. Judgment of September 7, 2004. Series C No. 114, para. 158, and Case of López Álvarez, supra note 149, paras. 111-112. See also, Case of Montero Aranguren et al. (Catia Detention Center), supra note 179, para. 104. 203 Cf. Application presented by the Commission, supra note 3, paras. 42 and 55 (folios 111 and 114); statement made before notary public (affidavit) by Yvon Neptune, supra note 6, para. 15 (folio 451); statement