INTRODUCTION: Police violence has been shown to harm the health of minority communities in the United States. However, limited research has examined how police killings impact adolescent self-concept, particularly across racial groups. This study investigated the divergent impact of exposure to police killings on self-esteem and self-efficacy among Black and White youth. METHODS: Longitudinal survey data were collected from 1818 middle school students (53% White, 47% Black
55% female) in St. Louis, USA between 2017 and 2018. Respondents living within two miles of a police killing in the 30 days before survey administration were considered exposed. Hybrid random-effects models were used to examine within- and between-person associations between exposure to police killings and self-concept. RESULTS: Black youth reported much lower self-esteem (Δ = -0.342, p <
0.001) and self-effacy (β = -0.439, p <
0.001) during survey waves in which they had been exposed to a recent police killing compared to during survey waves when they had not. Conversely, White youth reported significantly higher self-esteem (β = 0.112, p <
0.05) and self-effacy (β = 0.177, p <
0.001) during survey waves in which they were exposed to a recent police killing. CONCLUSIONS: Exposure to police killings has a racially polarizing "zero-sum" effect on adolescent self-concept, harming Black youth while bolstering White youth. This suggests police violence may reinforce racial hierarchies by undermining the psychological well-being of minority adolescents. These findings underscore the importance of considering race-specific mechanisms when examining community impacts of police violence.