17 alternative measures; the absence of mechanisms for implementing alternative measures; the inversion of the burden of proof, with which it falls to the accused to provide that pretrial detention should not be ordered; deep-rooted judicial paradigms and practices that favor pretrial detention over other measures; corruption; the widespread use of this exceptional measure in cases of minor offenses; and extreme difficulties in revoking it once it has been ordered. 44. Consequently, the Inter-American Commission has presented States with the following concrete recommendations: take the necessary steps to correct procedural delays and strengthen justice systems; adopt precautionary measures other than imprisonment in the pretrial phase; ensure that judicial authorities duly ground their orders for pretrial detention, in strict compliance with the maximum legal duration and in accordance with international standards, and to review those decisions periodically, ensuring that the reasons on which the pretrial detention was based continue to exist; ensure that people facing prosecution have effective judicial remedies to challenge pretrial detention orders; establish effective and accessible public defense systems; introduce the statutory amendments necessary to limit the use of such measures, particularly when nonviolent and less serious offenses are involved; promote an authentic change of paradigm and attitudes to the applicability of and need for pretrial detention; and take the necessary steps to ensure the independence of the judiciary, and the independence and autonomy of public defense services. 45. The Inter-American Commission has observed that measures intended to reduce the high numbers of people held in pretrial detention should address the implementation of controls over its use and seek to expedite criminal cases. It has also held that notwithstanding such circumstantial or creative actions that States may adopt, resolving this problem demands the adoption of serious legal and institutional reforms, arising from public policies that are geared toward that goal. Moreover, the IACHR has considered it essential that convicts and pretrial detainees be held separately, and that the latter group receive a treatment that is in line with the presumption of innocence. 46. Likewise, those United Nations mechanisms that monitor the situation of people deprived of liberty and, in particular, conduct oversight visits, have also addressed the high numbers of persons in pretrial detention in the OAS member States and the conditions in which they are held. 47. During its March 2013 visit to Brazil, the Working Group on Arbitrary Detention noted that of a total prison population of some 550,000 people – one of the 57 highest in the world – approximately 217,000 inmates were being held pending trial; in El Salvador, in January 2012, it reported that of a total of more than 25,400 people deprived of liberty, 7,376 were in pretrial detention, and 970 of them had been there 57 UN, Working Group on Arbitrary Detention, Statement upon Conclusion of its Visit to Brazil (18 to 28 March 2013), available at: http://www.ohchr.org/EN/NewsEvents/Pages/DisplayNews.aspx?NewsID=13197&LangID=E.