How police are trained to interrogate suspects raises the question of how police actually interrogate suspects in practice. Although very little research has examined police interrogation training, more scholarship has explored the techniques police use during interviewing and interrogation. Kassin and colleagues’ defining work in this area (Kassin ; Kiechel, 1996; Kassin ; McNall, 1991) introduced the concepts of minimization and maximization in police interrogation. Both have been described as “packages” of techniques, the former involving offers of sympathy, excuses, or face-saving justifications, whereas the latter involves intimidation, confrontation, and presentation or exaggeration of incriminating evidence. Researchers have expanded the study of interrogation techniques by identifying dozens of individual interrogation strategies in numerous different contexts. For example, Leo (1996) identified 25 disparate techniques used in his direct observation of interrogations in two California police departments. Pearse and Gudjonsson (1997) compared the use of nine different interrogation techniques among officers in two London-area police agencies. Soukara, Bull, Vrij, Turner, and Cherryman (2009) analyzed 80 audio-recorded interrogations from the United Kingdom to examine the frequency of 17 interrogation tactics.
Only three studies have systematically surveyed actual criminal interrogators about the practices they implement in the interrogation room: Kassin et al.’s (2007) questionnaire with U.S. and Canadian police officers and two (related) studies pertaining to juvenile interrogations (Kostelnik & Reppucci, 2009, Meyer & Reppucci, 2007, discussed in the next section; see Redlich, Kelly, & Miller, 2014, for a survey of federal investigators and Feld, 2013, for perspectives from police interviewees). Kassin et al. (2007) were the first to assess police officers’ self-reported attitudes and behaviors for a variety of interrogation-related constructs, including true and false confessions, detection of deception, and frequency of use for 16 various interrogation techniques, later factor analyzed into four factors. They reported that suspect isolation, rapport building, and identifying contradictions in the suspect’s story were among the most frequently used strategies, whereas physical intimidation, threats for noncooperation, and expressions of impatience/anger were rarely used. The study also included a single dichotomous variable pertaining to interrogation training and preliminarily explored the impact of training on technique usage. Eighty-two percent of the overall sample indicated that they had received some sort of training (11% of those indicated the Reid Technique). The dichotomous training/no training variable (type unknown) predicted officers’ self-reported use of two of the technique factors: Isolation, rapport and minimization, and Presentation of evidence.