The Police Interview Competency Inventory – PICI – is a five dimensional instrument to assess interviewing competences (De Fruyt et al., 2006). Based on selfrated interview competences this tool for police interviewers enables quantitative comparison among interviewers, but also has high potential for assessment and development purposes. The aim of the present study is to further elaborate on and replicate the findings of the PICI measurement instrument. We do so by investigating the internal consistency and the correlational validity of the PICI instrument. Guided by the aforementioned study of De Fruyt et al (2006) the current study first extended the initial used competences item list to include nine new competence items, which were not previously identified. Second, whereas the previous sample consisted of 230 experienced police interviewers, the present
research population has been enlarged with inexperienced police investigators creating a more general and representative police sample of 549 police officers. We hypothesized that the extra-added interview competences or items will not influence the stability of the police interviewing competency construct, and assumed that experience has no effect on police interview competences. The data provides strong support for both these hypotheses. Results show that the new defined competence items have no additional value in relation to defining the interview competences structure. Results also show that experience has no general predictive value in relation to individual competences differences. The results are theoretically consistent and therefore provide strong evidence concerning a
nomological interviewing competency network representing construct validity. Moreover, the present outcome resulted in highly identical results suggesting that the PICI measurement instrument is rather stable.

Keywords: Investigative interviewing, personality, PICI, external and internal
validity of interview competences, reliability.