This article aims to contribute to the empirical literature that deals with the relationship between moral beliefs and the use of force by police officers. We, therefore, develop an integrative action theory in which we combine the key principles of Situational Action Theory (Wikström, 2010) with the major insights of Muir (1977) and Mesko and Tankebe (2015) on how police officers cultivate legitimacy in their own police role. By means of a paper-and-pencil survey amongst 137 (mainly Belgian) police officers we test two main hypotheses: (1) To what extent does perceived audience legitimacy, self-legitimacy and police officers’ beliefs about the use of social skills predict their beliefs about the use of force? (2) To what extent do those attitudes and moral beliefs predict the actual use of force? First, we found that the less police officers are concerned with other people and the more they believed that citizens had no trust in or respect for the police, the more likely it is that they morally support the use of force. Second, we determined that police officers who are morally supportive towards the use of force are more likely to use force.