The PSI Lab studies how police agencies prepare for and respond to demonstrations, protests, major public events, and other crowd situations. Our research examines how police strategy, officer decision-making, crowd-management tactics, and interactions between police and participants can influence escalation, de-escalation, public safety, civil liberties, and perceptions of police legitimacy.

This work includes research on protest policing in the United States and internationally, evaluations of police responses to major crowd events, and studies of how members of the public interpret police action—or inaction—during moments of disorder. PSI also works with police agencies and other partners to translate research on crowd behavior and public-order policing into practical guidance for planning and response.