Purpose Procedurally just policing positively affects legitimacy regardless of differences in some demographic and neighborhood characteristics. Yet, less is known about how critical citizen views of police influence the effect of procedural justice on legitimacy. Citizen Black Lives Matter (BLM) support is an indicator of views toward police and provides a useful measure to test the procedural justice invariance thesis. The purpose of this study is to examine if BLM support moderates the effect of procedural justice on legitimacy.

Design/methodology/approach Data from a survey experiment of Americans (n = 363) are used to explore whether BLM support moderates the effect of procedural justice on legitimacy.

Findings Results suggest BLM support is negatively associated with encounter-specific perceptions of police legitimacy and provides tentative evidence suggesting BLM support moderates the effect of the decision-making element of procedural justice on legitimacy. Specifically, the interaction suggests that at higher levels of BLM support, procedurally unjust decision-making reduces legitimacy. However, there was little erosion of legitimacy among BLM supporters during procedurally just encounters.

Originality/value This study tests the procedural justice invariance thesis in a BLM context. Results support an association between BLM support and encounter-specific perceptions of police legitimacy and provide preliminary evidence that the effect of procedural justice on legitimacy may vary by levels of BLM support.