Police interviewers in English-speaking countries increasingly conduct interviews via an interpreter with suspects and witnesses who do not speak English. Oral communication in an official interview has serious legal consequences, beginning with Miranda rights or similar cautions. Past studies have yielded inconsistent results on key issues such as interpreting accuracy, changes in interpreter placement, remote versus face-to-face interpreting, and interviewer–interviewee rapport. To foster a robust and coherent scientific evidence base, this review synthesizes and integrates findings from the field and the laboratory. Interpreting procedures in Australia, Europe, and the United States of America are compared. The core of the chapter is an analysis of sources of research disparities which hinge on methodological differences in experimental assessments of interpreting performance. Prominent research gaps are identified regarding the optimal interpreting mode in police interviews, the interpreter’s role, assessment of interpreting performance, maintenance of investigative interviewing strategies, remote interpreting, and the effects of interpreting on witness credibility. Building on this review, future transdisciplinary research can develop empirically sound standards and best practice guidance and training for interviewers and interpreters. Implications of the findings are specified for courts, legal practitioners, and juries.