abstract: Discretion is central to policing. The way officers use their discretion is influenced by situational, officer, and neighborhood-level factors. Concerns that discretion could be used differentially across neighborhoods have resulted in calls for increased police transparency and accountability. Body-worn cameras (BWCs) have been promoted to further these goals through increasing oversight of police-citizen encounters. The implication is that BWCs will increase officer self-awareness and result in more equitable outcomes. Prior researchers have largely evaluated the direct impact of BWCs. Researchers have yet to examine the potential for BWCs to moderate the influence of neighborhood context in individual incidents. To address this gap, I use Phoenix Police Department data collected as part of a three-year randomized-controlled trial of BWCs to examine variation in police discretion. These data include over 1.5 million police-citizen contacts nested within 826 officers and 388 neighborhoods. I examine two research questions. First, how do proactivity, arrests, and use of force vary depending on situational, officer, and neighborhood contexts? This provides a baseline for my next research question. Second, examining the same contexts and outcomes, do BWCs moderate the influence of neighborhood factors on police behavior? As such, I examine the untested, though heavily promoted, argument that BWCs will reduce the influence of extralegal factors on officer behavior. Using cross-classified logistic regression models, I found that situational, officer, and neighborhood factors all influenced proactivity, arrest, and use of force. BWCs were associated with a lower likelihood of proactivity, but an increased likelihood of arrest and use of force. Officers were more proactive and were more likely to conduct arrests in immigrant and Hispanic neighborhoods. The moderating effects suggest that officers were even more likely to proactively initiate contacts and conduct arrests in immigrant and Hispanic neighborhoods when BWCs were activated. However, after BWCs were deployed, use of force was significantly less likely to occur in black neighborhoods. Given that high-profile police use of force incidents involving black suspects are often cited as a major impetus for the adoption of BWCs in American police agencies, this finding is a key contribution to the literature. / Dissertation/Thesis / Doctoral Dissertation Criminology and Criminal Justice 2020