methods of preventing, detecting, investigating and solving crime. It is also seen as one of the most effective approaches to counter terrorism when compared with traditional methods still applied by many police forces. This in turn has a positive impact on the outcome, fairness, efficiency and reliability of any subsequent criminal proceedings, and on how the general public perceives the police service. 80. The investigative interviewing approach has clearly inspired the CPT in its monitoring work. The Committee considers that all the police officers concerned should receive detailed guidance on how interviews with suspects should be carried out. This can be achieved through legislation, regulations or a set of rules, procedures or practices. By way of illustration, the CPT considers that, in principle, there should be no more than two interviewing officers. The authorised duration of an interview, the rest periods between interview sessions and breaks during an interview should also be clearly specified (for instance, interviews should last no more than two hours at a time and suspects should be allowed, within a time span of 24 hours, a continuous period of at least eight hours for rest, free from questioning or any activity in connection with the investigation). Police interviews should as a rule be carried out in rooms specifically designed and equipped for the purpose. The CPT has also recommended that a mechanism for the ongoing monitoring and systematic review of these police interviewing standards, procedures or practices be established. Further, the development of adequate initial and ongoing professional training on interviewing techniques is key in the effective implementation of any such framework for police interviewing. 81. The CPT has also stressed the importance of accurate recording of all police interviews (including the start and end times and the names of all persons present during the interview). The electronic recording of police interviews (with audio/ video-recording equipment) has also become an effective means of preventing illtreatment during police interviews whilst presenting significant advantages for the police officers involved. Electronic recordings should be kept securely for a reasonable period, be made available to the detained persons concerned, and/or their lawyers, and be accessible to representatives of international and national monitoring bodies (including NPMs), as well as to any officials responsible for investigating allegations or reports of police ill-treatment.16 Centralised police detention and designated custody officers – a promising practice 82. In a number of countries, the CPT has observed and encouraged a trend consisting of keeping persons in police custody in centralised police detention facilities rather than in police cells located in smaller establishments or special operational departments. 16. In parallel, the CPT considers that greater emphasis should be placed on a physical evidence-based approach and on modern, scientific methods of criminal investigation, namely seizure, retention, packaging, handling and evaluation of forensic exhibits and the chain of custody. In addition, ready access to up-to-date scientific tools, such as DNA technology and automated fingerprint identification systems, should be ensured (if necessary through investment in equipment). Page 34 ►General Report of the CPT, 2018