CAT/C/KOR/CO/3-5 accordance with international standards and enable the referral of inmates requiring specialized medical care to outside medical facilities; (c) Ensure that restraints are used only as a measure of last resort, for the shortest time possible and only when less intrusive alternatives for control have failed, and ensure the strict monitoring of the implementation of article 99 (2) of the Administration and Treatment of Correctional Institution Inmates Act; (d) Consider using non-custodial measures and alternatives to detention in keeping with the United Nations Standard Minimum Rules for Non-custodial Measures (the Tokyo Rules); (e) Provide age- and gender-disaggregated data on detainees covering the reporting period. Solitary confinement 23. The Committee is concerned that inmates are frequently placed in solitary confinement, as a disciplinary measure, for periods of up to 30 days, without strict medical monitoring and without the possibility of appeal (arts. 2, 11-13 and 16). 24. The State party should: (a) Amend current legislation in order to ensure that solitary confinement remains an exceptional measure of last resort, applied for a duration that does not exceed 15 days, and that it is imposed in line with international standards; (b) Ensure that the detainees’ due process rights, such as the right to an independent hearing and to appeal, are respected when subjecting them to solitary confinement and that the disciplinary committee acts with impartiality; (c) Establish clear and specific criteria for decisions on isolation and ensure that renewing and prolonging disciplinary sanctions of solitary confinement is strictly prohibited (d) Ensure that detainees’ physical and mental condition is monitored daily by qualified medical personnel throughout the period of solitary confinement. “Substitute cells” in police stations 25. While taking note of the closure of several “substitute cells” in police stations and that only four remain in operation, the Committee is concerned at the poor material conditions, including overcrowding, extremely small investigation detention rooms and insufficient privacy of sanitary facilities, in particular for women, who are supervised by male staff (arts. 11-14 and 16). 26. The State party should close the remaining “substitute cells”, take urgent measures to bring conditions in still existing “substitute cells” in line with relevant international standards and ensure that female police officers supervise “substitute cells” in which women are detained until they are closed. Deaths in custody 27. The Committee is concerned about the high number of suicides and sudden deaths in correctional facilities. It is particularly concerned that a large number of deaths in custody is due to the absence of adequate medical treatment for inmates suffering from diseases and that autopsies may not always be carried out and therefore cannot be used as evidence in criminal and civil cases. The Committee is also concerned about the very high number of persons in pretrial detention who have committed suicide that may be the result of coercive investigation procedures by police and prosecutors (arts. 2, 11-14 and 16). 28. The State party should: (a) Conduct an in-depth study into the causes of suicides and sudden deaths in correctional facilities and take all other measures necessary to reduce the number of suicides and sudden deaths; 7