Implementing the Méndez Principles in a Confession‐Oriented Culture: A Pilot Study of Investigative Interview Training in a Brazilian Police Academy

The Méndez Principles offer an evidence‐based alternative to confession‐oriented, coercive practices. This study examines the implementation of a training module aligned with the Méndez Principles in the basic course of the Civil Police of Goiás, Brazil. It is set in a context historically marked by the centrality of confession, intuition, and nonverbal cues as supposed indicators of lying. An 8‐h theoretical module on investigative interviewing and interrogation was offered to 484 candidates, who answered, before and after the training, the Suspect Interrogation Practices Scale, composed of items on Recommended and Non‐Recommended Techniques. The results indicated significant changes in most items, with increased endorsement of recommended techniques and reduced endorsement of non‐recommended techniques. Most significant changes were identified regarding the use of open questions, closed questions and reliance on non‐verbal cues to detect deception. The findings suggest that even brief, theoretical training can reorient perceptions about investigative interviews in a confessional system, without diluting the normative core of the Méndez Principles.