Evidence-based investigative interviewing of suspects

A/Prof. Stephen Moston1

1Forensii, Townsville, Australia


The adoption of evidence-based policing has had a profound effect on many aspects of policing, but there remains one glaring omission: training and practice in the investigative interviewing of suspects.  Police in Australia and New Zealand are adapting the UK PEACE based training model, for interviews with suspects (and witnesses). This presentation evaluates the extant evidence base for the PEACE model with suspects. To date, there have been few evaluation studies, most featuring non-police samples. Results show that there is remarkably little evidence that the PEACE approach with suspects is effective. Many of the elements in training courses are ineffective, producing no discernible improvements, and some are actually detrimental to performance in interviews with both suspects and witnesses. To counter this evidence base, advocates of PEACE rely on anecdotes , co-opting evidence from other contexts and unverifiable claims, such as the adoption of PEACE resulting in a reduction in miscarriages of justice. A reliance on such weak forms of evidence is often an indication that a claim is pseudoscientific, and it is clear that much of what passes as interviewing science is in reality pseudoscience. Talking to people, be it a victim, witness or suspect is a core part of policing. Significant progress has been made on the interviewing of victims and witnesses, but it is now time to establish a science of interviewing suspects. This requires an evidence-base. This will mean opening up police investigative processes to both internal and external scrutiny, and therein lies the real problem.


Stephen’s groundbreaking work on interviewing children changed the way that child witnesses are questioned. His subsequent work with the Metropolitan Police included creating a new information-gathering approach to questioning suspects, which Stephen labelled “investigative interviewing”. This approach would become the foundation for the PEACE technique which has been the basis for police training in many countries for over twenty-five years. Stephen has been teaching legal and forensic psychology in Australia since 1992. He has been Head of Postgraduate Training in Forensic Psychology at two Australian Universities.