How does ethnic politics affect the state's ability to provide policing services? Using a panel of administrative personnel data on the full careers of 6,784 police officers, we show how the rise of ethnic politics around Kenya's independence influenced policemen's behavior. We find a significant deterioration in discipline after Kenya's first multiparty election for those police officers of ethnic groups associated with the ruling party. These effects are driven by a behavioral change among these policemen. We find no evidence of favoritism within the police. Instead, our results are consistent with co-ethnic officers experiencing an emboldenment effect. Our findings highlight that the state's security apparatus, at its most granular level, is not insulated from ethnic politics.