Given the vast amount of evidence showing the substantial influence of emotion on decision-making, we examined emotionality—a person’s emotional reactivity to a stimulus—in police use-of-force decision-making between a sample of expert (n = 42) and novice (n = 36) officers. Officers observed body-worn camera footage and described the course of action they would take, the kinds of information they paid attention to, and their assessment of the situation. Natural language processing techniques were used to detect measures of valence, arousal, and dominance from officer responses. Linear mixed-effects models indicated that responses from experts were more positively valenced, more dominant, and less arousing compared with responses from novices. In other words, the ability to react and assess situations calmly, with a greater sense of control, and less negatively seems to be linked with the production of accurate, effective, and efficient behaviors that mark expert policing. These results shed light on the ways in which expert and novice officers understand and experience stimuli involved in use-of-force decision-making. Practical implications for use-of-force training and future directions are discussed.