The use of interpreters in investigative interviewing settings is increasingly common as societies have become more diverse and interconnected. Interpreters serve as vital players in interviewing contexts ranging from interviewing witnesses in police interviews to the collection of intelligence from human sources when threats to national security are present. However, the study of the role and impacts of interpreter presence in such settings has received very little attention until recently. This chapter describes the current state of the literature as it relates to interpreters in investigative interviews. Specifically, we discuss the role of interpreters in law enforcement and intelligence gathering contexts and summarize the relevant research regarding: interpreter influence as a function of seating position, information loss and gain in interpreter-mediated interviews, errors in translated statements, and deception detection. We conclude with the need for research in areas such as emotional trauma to interpreters as a result of exposure to violent crime and the potential influence of bias in interpreted statements, and we discuss potential training requirements and standards for interviewers and interpreters.