A/HRC/20/24 guarantee systems”. The European Union Returns Directive 7 provides that a third-country national who is the subject of return procedures may not be held in detention if other sufficient but less coercive measures can be applied effectively in a specific case. 52. The Special Rapporteur would like to stress that alternatives to detention should not become alternatives to unconditional release. Persons who are eligible for release without conditions should not be diverted into alternatives. 53. In the Special Rapporteur‟s view, the obligation to always consider alternatives to detention (non-custodial measures) before resorting to detention should be established by law. Detailed guidelines and proper training should be developed for judges and other State officials, such as police, border and immigration officers, in order to ensure a systematic application of non-custodial measures instead of detention. Non-custodial measures should be subject to legal review, and migrants who are subject to non-custodial measures should have access to legal counsel. When considering alternatives to detention, States must take full account of individual circumstances and those with particular vulnerabilities, including pregnant women, children, victims of trafficking, victims of torture, older persons and persons with disabilities. The least intrusive and restrictive measure possible in the individual case should be applied. Legislation should establish a sliding scale of measures from least to most restrictive, allowing for an analysis of proportionality and necessity for every measure. Some non-custodial measures may be so restrictive, either by themselves or in combination with other measures, that they amount to alternative forms of detention, instead of alternatives to detention. When considering whether the measures applied amount to detention, the cumulative impact of the restrictions as well as the degree and intensity of each of them should also be assessed. 54. Non-custodial measures must conform to relevant principles of international law, including the principles of non-discrimination, necessity and proportionality and should not prevent individuals from exercising their other human rights, including the right to health and education. Alternatives to detention which impose restrictions on the liberty of movement need to be in compliance with article 12 of the International Covenant on Civil and Political Rights, which provides for the right to liberty of movement for everyone lawfully within the territory of a State. The term “lawfully within the territory” has been held to apply to persons who are allowed to remain in a country because the host State is unable to carry out an expulsion or deportation order (Human Rights Committee, communication No. 456/1991). Article 12, paragraph 3, of the Covenant provides that any restrictions on the right to liberty of movement must be provided by law, and be necessary to protect national security, public order, public health or morals or the rights and freedoms of others. 55. The United Nations Standard Minimum Rules for Non-Custodial Measures, although they relate to non-custodial measures in the criminal justice system, may by analogy provide some important guidance on non-custodial measures applied to migrants. The rules provide, inter alia, that the introduction, definition and application of noncustodial measures shall be prescribed by law, decisions on the imposition of non-custodial measures shall be subject to review by a judicial or other competent independent authority, the person subject to non-custodial measures shall be entitled to make a request or complaint to a judicial or other competent independent authority on matters affecting his or her individual rights in the implementation of non-custodial measures, the dignity of the person shall be protected at all times, and the right to privacy shall be respected. Furthermore, the most suitable type of supervision and treatment should be determined for each individual case, and supervision and treatment should be periodically reviewed and 7 14 Directive 2008/115/EC of 16 December 2008.