A/HRC/7/4 page 20 − On the right to be brought promptly before a judicial or other authority after having been taken into custody; − On the necessity of founding the decision on custody on criteria of legality established by the law by a duly empowered authority; − On the desirability to set a maximum period of detention by law which must in no case be unlimited or of excessive length; − On the requirement of notification of the custodial measure in a language understood by the immigrant or asylum-seeker, including the conditions for applying for a remedy to a judicial authority, which shall decide promptly on the lawfulness of the measure and be competent to order the release of the person concerned, if appropriate; − On the obligation of States to place asylum-seekers or immigrants in premises separate from those persons imprisoned under criminal law. In all cases detention must not be for a potentially indefinite period of time. 53. The Working Group would further recall the obligation of States to consider alternatives to administrative custody from which the alien can benefit in accordance with Guarantee 13 as developed by the Working Group in its legal opinion on the situation regarding immigrants and asylum-seekers.14 In the view of the Working Group, criminalizing illegal entry into a country exceeds the legitimate interest of States to control and regulate illegal immigration and leads to unnecessary detention. 54. The Working Group was able to satisfy itself during country missions that there are alternatives to detention for illegal immigrants, which have been successfully implemented. In countries which allow for illegal immigrants to be taken into custody but refrain from resorting to administrative detention, the law provides for strong procedural safeguards, including the obligation to have a judge decide on the legality of and continuing reasons for detention, and generally only permits detention as a last resort. B. Groups in detention which are susceptible to sexual abuse 55. The Working Group is aware that certain vulnerable groups of detainees and prisoners are specifically susceptible to sexual violence by co-inmates and prison staff, including young women, minors, non-citizens, the poor, mentally disabled, indigenous people, and vulnerable men. This list is not exhaustive. The Working Group has made observations relating to this particularly disturbing trend during some of its country missions. It has received credible information that women and minors are subjected to sexual exploitation and abuse by prison staff or by their co-inmates in detention facilities. From its experience, the Working Group can verify that when juveniles are detained together with adults they are almost systematically subject to sexual abuse. As far as women are concerned, it has been regularly reported that 14 E/CN.4/1999/63, para. 69.