Little is known about the decision-making styles of active-duty police officers or what the consequences of not understanding those decision-making styles may be. The purpose of the study was to describe the demographics and decision-making profiles of active-duty police officers, as well as any relationships that may exist among these variables, and the effects of leadership training on decision-making styles. The general approach of this study involved a multi-case examination of quantitative data, both new and historical, regarding the decision-making styles of active duty police officers as determined by the General Decision-Making Styles (GDMS) survey. This research used a quantitative, comparative, multiple-case, descriptive design comprising three data sets. Results from two previous studies and a new study conducted for this research were analyzed to determine if a profile of decision-making styles emerged for those choosing an occupation as a police officer. An online questionnaire gathering demographic data as well as the GDMS responses were combined with an intra-departmental study and a study from research conducted in 2003. The study also examined the potential effects of leadership training for police officers on their measured decision-making style. The study was guided by six theoretical concepts: Adult Learning, Transfer of Training/Learning, Career Choice Models, Leadership Development, General Decision-Making Style, and Decision-Making in the Community Policing context. Analysis of the data revealed a strong relationship with those choosing a career in policing and the Rational decision-making style. In contrast, a strong negative relationship also emerged with the participants and the Avoidant decision-making style. Research strongly indicates that decision-making styles may be situational but that the primary style will resist change and remain dominant in arriving at a decision. Since decision-making styles are unlikely to change with time or through intervention, it is important to consider using the GDMS as a screening tool for future police candidates. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]