E/CN.4/2003/8/Add.3 page 16 even though, at the same time he is being asked to cooperate. The potential combination of these practices with a possible campaign of “zero tolerance” risks aggravating the harmful effects of these detentions. E. The system for enforcing sentences and the risks of arbitrary detention 43. In the enforcement of criminal penalties, the actual duration of sentences is ultimately determined by the administrative authorities entitled by law to modify sentences substantially without being subject to control by the ordinary courts. The length of the sentence does not necessarily depend on the nature of the offence and the convicted person has no opportunity at this stage to challenge the decision before a judge. 44. Another concern arises from the 1994 reforms, which introduced an excessive number of serious offences that in practice had a negative impact in terms of prison overcrowding. The subsequent ban on early release for those offences (particularly drug offences), which can be disproportionate in comparison with other offences for which early release is possible, creates a sense of injustice among inmates, as the Working Group was able to ascertain in its interviews with prisoners. F. Curfews and arbitrary detention 45. At the request of the Public Prosecutor’s Office, a judge will issue a home-curfew order or order banning a person from leaving a specific geographical area if a criminal case is being prepared against that person and there is a reasonable risk that the person might abscond. 46. When article 133 bis of the Federal Code of Criminal Procedure was amended, curfew orders were introduced primarily to avoid the use of administrative detention while at the same time guaranteeing that a person could be located and brought before the court, thereby avoiding sending him to prison unnecessarily. In practice, however, curfews have become a form of preventive detention, often enforced in a “curfew house” or, sometimes, in a hotel. 47. The practical consequence of this kind of curfew is that it gives the Public Prosecutor’s Office longer to carry out the relevant investigations and collect the evidence it needs to submit to the district judge before the person can be formally charged. 48. There is thus a sort of de facto pre-trial that takes place not before a judge, but before officials from the Office of the Attorney-General, who are thus empowered to perform judicial acts and evaluate evidence and present the means of proof before the person is charged. 49. The Working Group heard criticisms of the way in which this measure is implemented in so-called “curfew houses”, which might be houses confiscated from drug-traffickers or fraudsters or rooms rented in hotels to enforce curfew orders. Detainees are then subject to curfew not in their homes, but in this kind of private establishment, which is actually very similar to a prison (in terms of security, numerous armed guards, electronic surveillance, etc.). 50. After visiting one of these curfew houses, the Working Group finds that this arrangement in fact amounts to a form of preventive detention of an arbitrary nature, given the lack of