Investigative interviews with suspects are complex interpersonal interactions that are focused on eliciting statement evidence to use within subsequent investigative and judicial processes. When conducting an investigative interview, criminal investigators face a series of decision points – involving potentially competing alternatives – which collectively determine how the interview will unfold. These decisions are also made under real-world constraints of limited time and knowledge. Interviewer decision-making, therefore, is both psychologically complex and practically consequential. In the present chapter we examine the role of interviewer decision-making across five dimensions of investigative interviewing: Why (is an interview conducted?), Who (will participate?), When and Where (will the interview occur?), and What (techniques will be used?). We use this structure to outline the current state of the literature on suspect interviewing best practices and how each decision point raises factual and ethical considerations for interviewers, interviewees, and the criminal justice system more broadly. We conclude by discussing potential future directions for research that can continue to inform effective decision-making in this area.