Engage and explain, Account, and Closure phases in mock witnesses’ investigative interviews

Evidence-based investigative interviewing protocols are central to the training of police investigators. While past research has focused on analyzing the questioning types and styles used by police officers, there is growing interest in the Engage and explain, Account, and Closure phases of the interview. The objective of our study was to analyse the use of evidenced-based interviewing techniques advocated in the Engage and explain, Account and Closure phases of the interview among experienced police officers at the beginning and at the end of a training course. We evaluated 28 mock witness investigative interviews conducted by 14 police officers, half of whom had previously received training in an evidence-based interviewing technique, using a scoring grid of 14 recommended interviewing techniques. The results showed that at the end of a training they used an average of 11.2 components whether they had been previously trained or not, but that there is room for improvements. Future research and training recommendations in evidence-based investigative interviewing protocols are discussed.