This study examined the effects of case-specific facts and individual discomfort with ambiguity (DA) on investigators' beliefs concerning effective interviewing tactics for suspects. Violent crime investigators (n = 30) responded to a questionnaire including the Need for Closure Scale (NFCS) and ratings of the importance of 39 interrogation tactics in two hypothetical interrogations with a homicide suspect, where the evidence consisted of either technical evidence or soft information. Twenty tactics were analysed with a multidimensional scaling procedure which confirmed two discrete interviewing themes: humane and dominant. More tactics, both dominant and humane, were rated as important if the evidence was soft compared with technical. In the soft evidence condition, investigators who were high on DA rated both types of tactics as more important than did low-DA investigators. In the technical evidence condition, no such difference emerged. Copyright © 2008 John Wiley & Sons, Ltd.