At the center of a criminal investigation is the ability of the lead investigator to identify all possible hypotheses, make sense of the information available and define appropriate investigative actions. These characteristics are usually dependent on what has been termed as investigative decision making, the process where an investigator analyzes the evidence and decides which actions to take. Previous research and reports have identified situational, organizational, and individual factors that may hinder or improve investigative decision-making. The present paper aims to identify which individual factors have been empirically tested concerning investigative decision making, and how they affect it. A systematic review was conducted, nine peer-reviewed papers were analyzed, and five factors were identified: Experience, Gender, Need for Cognitive Closure (NFC), Time-urgency, and Fluid Intelligence. Experience had mixed findings, suggesting that how officers developed expertise is more important than time on the job. Gender was only significantly related to investigative decision-making in a specific scenario. Low NFC, non-time-urgent individuals, and high fluid intelligence were related to effective investigative decision-making. Recommendations for the future academic development of the field, and how police forces can apply this knowledge are suggested.