19 50. Over the past fifteen years, the Universal System mechanisms have also noted that the high rates of pretrial detention are the result of factors such as the trend to use it as the first alternative; legal restrictions on precautionary measures other than pretrial detention for certain offenses; judges’ reluctance to order alternative measures, even when provided by law; the institutional weaknesses of public defense services, and their lack of independence; barriers to access public defense services; shortcomings in the decision process prior to which pretrial detention is applied, particularly with respect to the right to be heard with due guarantees; the absence of effective judicial remedies to challenge illegal or arbitrary pretrial detention orders; the widespread use of the measure in cases involving minor offenses; pressure on judges from the media and from other State agencies; structural shortcomings in judicial systems, particularly judicial delays; and “hard line” criminal justice policies. 51. UN mechanisms have also regularly issued the following recommendations to the region’s States: use pretrial detention only when there are no other means to ensure the appearance of the accused at trial or to prevent tampering with evidence; interpret restrictively the circumstances in which pretrial detention can legally be ordered; review the laws and judicial practices to ensure that the measure is used only in exceptional cases and for the shortest time possible; implement other precautionary measures, such as bail, house arrests, or electronic bracelets; review laws restricting judges’ power to order measures other than pretrial detention; ensure that decisions ordering pretrial detention are taken after a substantive analysis of the case and not merely a formal review; ensure that the conditions in which pretrial detainees are held are in line with international standards; ensure that detainees enjoy the possibility to prepare their defense at trial, as well as the necessary conditions to do so; and strengthen the operational capacities of the authorities responsible for criminal investigations (public prosecutors). B. Statistics submitted by the States 52. As noted in the introduction, in the context of this report, a questionnaire was sent to the OAS member States asking them for information on several issues related to the use of pretrial detention in their jurisdictions, including data on the percentage of the total prison population held in pretrial detention, disaggregated by sex and by type of crime (Question No. 2). The information furnished 64 by the States that responded the questionnaires is the following: 64 Sources: Bolivia (not specified), Brazil (Infopen statistics, National Penitentiary Department of the Ministry of Justice – Depen/MJ), Chile (daily reports of prison population, Gendarmerie of Chile), Colombia (consolidated statistics, National Penitentiary Institute of Colombia, INPEC), Costa Rica (SIAP, Penitentiary Administration Information System), Ecuador (Ministry of Justice, Human Rights, and Worship), Guatemala (Penitentiary System Directorate, MINGOB), Honduras (Directorate of Special Preventive Services of the Secretariat of Security), Panama (Department of Statistics of the Interior Ministry’s Directorate of Administration and Finance), Paraguay (General Directorate of Penitentiary Establishments and Execution of Criminal Penalties), Peru (statistical reports of the National Penitentiary Institute, INPE), Uruguay (Directorate of Statistics and Strategic Analysis of the Interior Ministry), Venezuela (Coordination Unit for Public Defense Procedural Actions).