Motivational interviewing (MI) is an evidence-based intervention that has proved effective across diverse clinical contexts with clients ambivalent about and resistant to behavioral change. This article argues that the principles of MI can be successfully applied to law enforcement (LE) interviews with high-value detainees (HVDs; i.e., terrorist suspects). Although the forms of ambivalence and resistance may differ from those in clinical contexts, HVDs must make the decision whether to talk or not when they are interviewed. We argue there is likely ambivalence regarding this. We theorized that 4 MI-consistent (MI) skills may be useful for LE interviewers: reflective listening, summaries, rolling with resistance, and developing discrepancies. Using the Observing Rapport Based Interpersonal Techniques coding manual (Alison, Alison, Elntib, & Noone, 2012), we analyzed 804 tapes of LE interviews with 75 terrorism suspects in the United Kingdom. Multilevel structural equation modeling revealed that MI skills encouraged detainee engagement and subsequent information gain. It also revealed that any approach antithetical to MI had a profoundly negative impact on detainee engagement and subsequent information gain—potentially through creating reactance (a form of resistance based on motivations to regain a freedom when it is threatened). Overall, this research provides unique evidence for the use of specific skills and approaches that can increase or decrease HVD engagement and information provided. Public Significance Statement: This article provides empirical support for using a humane, respectful, and compassionate approach to interrogating high-value detainees (i.e., terrorist suspects) to encourage cooperation and disclosure of information. These findings have potential to improve methods of national security while promoting fair treatment of detainees. [ABSTRACT FROM AUTHOR]