The Manual provides a synthesis of the author’s best knowledge as to what research recommends as best practice in conducting (investigative) interviews, transposed to inspection and audit. It builds on investigation-, intelligence- and negotiation literature, often drawing from the same insights in psychology, criminology and communication theory. Whilst the Manual was written to address recurring challenges expressed during his training of auditors and inspectors, it aims to be relevant for any professional interviewer. Rather than finding the correct, particular answer to a case example, it embraces the concept of expertise, that is: extracting by analogical reasoning, the underlying, more abstract insight(s), to be used when facing similar situations later.

Tom Willems is a senior investigator of fraud and corruption. He has conducted administrative and criminal investigations for national and international authorities throughout his career, and has been a trainer on interviewing almost from the start. He is lecturer on investigative interviewing at the International Anti-corruption Academy in Austria and member of the International Investigative Interviewing Research Group. He authored a book and several articles on interviewing in fraud and corruption cases, and is currently PhD-candidate at the University of Luxembourg on the same topic.