Tactical and incident commanders make decisions in the high-threat law enforcement context of hostage rescue, armed barricaded suspects, and armed suicidal individuals that can result in successful or catastrophic outcomes. This qualitative study offers more evidence—as an integral part of emerging research on education and reaching effective decisions to the current literature—by extending and detailing the decision-making process of commanders that occurs during a high-threat incident. It describes the experience and methods of making decisions in this environment. Furthermore, areas addressed by this research include learning strategies that could better prepare commanders in the processing of information, while optimizing speed and accuracy in decision-making. Particular attention was paid to the role of adaptive expertise in decision-making by understanding how mental models of recurring patterns, necessary for effective situational assessments, are created and subsequently retrieved. The purpose of this study was to explore through interviews, a survey, and focus groups how experienced tactical and incident commanders describe making decisions, and the factors impacting these decisions during events involving hostage rescue, armed barricaded suspects, and armed suicidal individuals. Participants described the necessity of having to adjust their decision-making process frequently in a high-threat situation. This process includes asking strategic questions to obtain actionable intelligence for making sound decisions when this information is not readily provided. Principal factors enabling participants to make sound decisions are good intelligence, the ability to make accurate situational assessments, and having sufficient resources. Additionally, experience as a prior team member and/or team leader, along with previous command mentoring are the key learning strategies that help or hinder participants when making decisions. A key practice recommendation resulting from this study is that command training programs should focus on adaptive decision-making and the critical aspect of determining safety and threat levels through reliable intelligence and good communication. This recommendation can benefit individual commanders, law enforcement agencies, and the communities they serve if improved command decision-making strategies result in fewer lives lost in a high-threatsituation.