Frontline state agents wield broad discretion over citizens’ access to public services, yet whether the attitudes shaping it can be changed among incumbent bureaucrats is largely unknown. Partnering with the Bihar Police, we run a cluster randomized trial across 417 stations and ~2,500 senior officers evaluating a three-day expressive arts intervention grounded in Theatre of the Oppressed to improve police responses to gender-based violence (GBV). Seven months after baseline, treated officers exhibit more favorable GBV attitudes, greater empathy, and stronger legal knowledge. These translate into behavior: in victim audits one year later, treated stations are 15 percentage points less likely to blame victims, dismiss fewer complaints, and provide more referrals, while records show a 41% drop in registration delays and, over a longer horizon, increased citizen GBV reporting. Exploiting transfers, we find suggestive evidence that effects persist as officers relocate and diffuse to untreated colleagues. Junior female officers under treated seniors report lower harassment and anxiety. Attitudes shaping bureaucratic discretion are malleable, and changing how state agents exercise authority can improve service delivery and workplaces.