–5–
information that “fits” and to ignore or explain away information that does not confirm what the
interviewer believes to be true) are the underlying causes of miscarriages of justice in most cases.
78.
Police interviewers with an open mindset are far more effective; they apply in practice the
presumption of innocence by generating and actively testing alternative hypotheses through
systematic preparation, empathic rapport-building, the use of open-ended questions, active listening,
and strategic probing and disclosure of potential evidence.
79.
Unsurprisingly, the investigative interviewing approach – combined with the practical
operation of procedural safeguards as from the very outset of deprivation of liberty – is gradually
achieving broad acceptance at universal level.12 It features a number of advantages: it dismantles
the myth of the effectiveness of harsh interrogation methods (including ultimately torture), and
replaces it with more effective 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 ill-treatment 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 illtreatment.13
12
See in particular the interim report of the United Nations Special Rapporteur on Torture (A/71/298, 5 August 2016),
who made a convincing case for the benefits of investigative interviewing and called for the development of a universal
protocol identifying a set of standards for non-coercive interviewing methods and procedural safeguards.
13
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).