b) Outdoor exercise yard In accordance with the Rules, PS which implement longer detention should have an appropriate outdoor exercise yard (with a surface of 12 m2 according to the Rules, and a concrete ashtray).9 During our visits, we established that not all PS which have detention rooms for longer detention (up to 48 hours) have an outdoor exercise yard. Furthermore, PS which do have an outdoor exercise yard have not equipped the latter with an appropriate, i.e. as stipulated, ashtray. It was established that Sežana PS, Velenje PS, and Šmarje pri Jelšah PS, even though they have and use detention rooms for longer detention (up to 48 hours), are not equipped with an appropriate exercise yard. It was therefore proposed that a possibility of setting up such a yard be studied. The MI responded that the possibility of setting up an appropriate outdoor exercise yard to enable outdoor exercise for persons deprived of their liberty would be studied. We recommended that Gornja Radgona PS, Murska Sobota PS, Gorišnica PS, and Ptuj PS put an appropriate ashtray in the outdoor exercise yard. The MI answered that ensuring an appropriate immovable ashtray depends on the technical possibilities and available financial resources. It needs to be said that the CPT already recommended that measures be adopted which would provide all people who are in police detention for 24 hours or more with the possibility of outdoor exercise during its 2012 visit to Slovenia. The CPT again pointed out this right during its 2017 visit. The CPT trusts that all newly built police stations will be equipped with an outdoor exercise yard. c) Permanent on-call services During the visits, we established that individual PS, e.g. Gornja Radgona PS, Lenart PS, and Kozina PS, have detention rooms but do not have a permanent (24-hour) on-call service. Consequently, detentions are not carried out at these PS and police officers must take persons deprived of their liberty to other (including more remote) PS. For these cases, it was recommended that the possibility of (again) setting up permanent on-call services be studied. The MI responded that the reintroduction of permanent oncall services was not anticipated for these PS. d) Video surveillance During the visits to Gornja Radgona PS, Lenart PS, Postojna PS, Ilirska Bistrica PS, Sežana PS, Nova Gorica PS, Velenje PS, Rogaška Slatina PS, Ribnica PS, and Kozina PS, it was established that individual rooms which are used for implementing procedures involving persons deprived of their liberty (mostly rooms for the admittance of persons deprived of their liberty, access halls to detention rooms, rooms for discussions with lawyers, interrogation rooms, and rooms for interviewing and processing foreign nationals), have still not been equipped with video surveillance. When preparing recommendations for the elimination of these deficiencies, we also referred to the CPT, which pointed out during its previous visits to Slovenia that electronic (audio and/or video) recording of police interviews (procedures) was an important safeguard against the ill-treatment of detainees, by ensuring a complete and authentic recording of the interview and consequently strongly facilitating the investigation of any claims of illtreatment. This was therefore in the interest of both the people who are supposedly ill-treated by the police, and police officers if they are faced with false claims of ill-treatment. Electronic recording of police interviews furthermore reduces the possibility of detainees later falsely denying giving a statement. During its 2017 visit, the CPT again encouraged the authorities to further promote the use of electronic equipment for recording police interviews as standard practice. With regard to our recommendations that facilities in PS which are intended for the admittance of detainees be equipped with a video surveillance system, the MI responded that the possibilities of setting up video surveillance would be studied. 9  The Police Tasks and Powers Act stipulates (in the second paragraph of Article 71) that a person who spends more than 12 hours in a detention room must be allowed outdoor exercise, unless this is not permitted for security reasons. 68 IMPLEMENTATION OF THE DUTIES AND POWERS OF THE NPM IN 2017 NATIONAL PREVENTIVE MECHANISM UNDER THE OPTIONAL PROTOCOL TO THE UN CONVENTION AGAINST TORTURE AND OTHER CRUEL, INHUMAN OR DEGRADING TREATMENT OR PUNISHMENT