Objectives <p>We examine whether an officer’s likelihood of using physical force during a 911 call response is associated with exposure to peers who have previously used force.</p> Methods <p>We use data on joint responses to 911 calls by Dallas police officers to reconstruct the social network of on-duty patrol interaction within the Dallas Police Department. Merging these data with Response to Resistance reports on use of force, we use a matched case-control design implemented with conditional logistic regression and permutation tests to estimate whether lagged and contemporaneous exposure to peers with a history of use of force is associated with an officer’s own likelihood of using physical force, holding constant incident-level situational context.</p> Results <p>Greater lagged exposure to peers’ prior use of force is associated with a higher likelihood that a focal officer subsequently uses physical force during a 911 response. In contrast, contemporaneous exposure is associated with a reduced likelihood of force in the same incident.</p> Conclusion <p>These findings are consistent with social learning perspectives suggesting that peer influence may operate through longer-term processes of learning and socialization while also shaping how officers coordinate behavior during specific encounters. More broadly, the results highlight the importance of considering how routine on-duty interactions shape police behavior and suggest that social networks may both reinforce and constrain the use of force.</p>