A/HRC/31/35 conditions in detention facilities adhere to the United Nations Standard Minimum Rules for the Treatment of Prisoners (the Nelson Mandela Rules) and other relevant standards.56 Alternatives to detention 46. The prohibition of arbitrary detention means that any decision to detain must be guided by the principles of reasonableness, necessity, proportionality and nondiscrimination. This requires States to contemplate other ways to achieve their objectives, such as considering alternatives to detention. 47. Around the world, however, there is a marked lack of human rights-compliant alternatives to detention, although research indicates that immigration detention is expensive, damaging to individuals and does not in general deter irregular migration. 57 48. An alternative approach respects migrants as rights holders who can be supported and empowered to comply with immigration processes without the need for detention, while at the same time achieving migration management objectives. 58 Research indicates that alternatives are most effective when a diversity of strategies and approaches that focus on constructive engagement and respect for human rights are used. Such successful alternative approaches include case management, legal assistance, social support and ensuring the protection of the rights to education, housing and health care. Alternatives to detention also increase the likelihood of compliance with return decisions; for instance, independent returns in the European Union and Australia result in savings of approximately 70 per cent compared to escorted removals.59 E. Violence, abuse and exploitation 49. While in transit, migrants are frequently at risk of violence, torture, abuse and exploitation at the hands of private and State actors. For example, more than half of the people interviewed for a report on the situation of sub-Saharan African migrants in transit in Morocco said that they had witnessed violence during the journey to Morocco and 43 per cent said that they had been a victim of some form of violence. Three quarters of those had experienced multiple episodes of violence.60 In addition to physical wounds, such violence has a profound impact on the mental health of the migrants. Perpetrators are often able to act with impunity and migrants are often reluctant to seek medical help, protection or justice for fear of arrest or other repercussions. 56 57 58 59 60 OHCHR, Recommended Principles and Guidelines on Human Rights at International Borders, guideline 8.7. International Detention Coalition, “Does, detention deter?” Briefing paper, 2015. The International Detention Coalition defines alternatives to detention as any legislation, policy or practice by which persons are not detained for reasons relating to their migration status. IDC has identified and incorporated a number of positive examples of alternatives to detention globally into a single framework, called the Community Assessment and Placement Model. See Robyn Sampson and others, There are Alternatives: A handbook for preventing unnecessary immigration detention (see footnote 47), pp. 2 and 19. Ibid., p. 52. See Doctors without Borders, Violence, Vulnerability and Migration: Trapped at the gates of Europe, p. 8. 13