This article explores the use of violence by police officers and gendarmes in Ghana and Niger. We analyse how popular discourses, legal and organizational conditions frame the police use of violence. Acts of violence by police are situated in this inconsistent framework and can be seen as legal and appropriate, despicable and brutal, or as useful and morally legitimate. Thus, every time the police use violence, they face a major dilemma: legally and morally justified violence can be a source of long-term legitimacy; but because of multiple possible readings of a certain situation (according to different, conflicting moral and legal discourses), the very same action has potentially delegitimizing effects. Our own position as participant observers made us aware of these contradictions because, as researchers, we were confronted with a similar dilemma.