Police use of force promotes protester violence: the mediating role of social identity and perceived procedural injustice in the context of police-protester relationships

In recent decades, the world has witnessed numerous violent demonstrations in which some protesters use violence to achieve their goals, and some police officers use violence to silence protesters. Drawing on the Elaborated Social Identity Model (ESIM) and procedural justice theory, we argue that police use of force increases activists’ identification with radical protesters and perceptions of procedural injustice. In turn, identification with radical protesters and procedural injustice should foster support for protester violence. We tested these hypotheses using three waves of longitudinal panel data (n = 1,514) from Chile collected after the 2019 Social Outbreak, which saw violence from both protesters and police. In our data, 404 protesters in wave 1 (31.69% of protesters) reported experiencing police repression, which allows us to examine its effect on identification with radical protesters, perceived procedural injustice, and the justification of violent collective action. Consistent with the ESIM, results reveal a significant positive correlation between experiencing police violence and identification with radical protesters across waves. In turn, identification with radical protesters correlated positively with the justification of protester violence. The effect of police violence on procedural injustice was, however, less clear. Although experiencing police repression did not directly impact perceptions of procedural injustice, it did so indirectly via identification with violent protesters. Procedural injustice also had a positive effect on the justification of protester violence. We conclude by discussing the implications of these results on the role of police in the escalation of violence and for promoting peaceful methods of protest.