Police organizations routinely train their officers on the use of deadly force policy and procedures. The topic addressed in this study is that deadly force policy training may be inadequate in combining policy along with discretion in shoot or no shoot situations often resulting in improper use of deadly force. The problem is the training that Illinois State Police (ISP) Troopers receive may not be perceived as adequately including critical thinking and the use of discretion. The purpose of this exploratory case study is to explore retired Illinois State Police Troopers perceptions of the inclusion of critical thinking and use of discretion in their deadly force policy training. Two central questions guide this study are: RQ1: How do retired ISP Troopers perceive the effectiveness of their deadly force training in preparing them for shoot or do not shoot training? RQ 2: How do retired ISP Troopers believe their training adequately includes the application of critical thinking and the use of discretion? This research is a bold endeavor to explore the inner workings of a police department and required the utmost confidentiality measures to protect the officers engaged in the study. Interviews were recorded with the permission of the participants and transcribed into word documents which were collated for similar themes using NVivo 10 software. Four emergent themes resulted from the collected data that revealed that enhanced training, critical thinking, and discretion are important for the best preparation for police deadly force encounters. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]