Despite considerable attention to gun violence, crime gun investigations have received limited empirical focus. Research suggests that reliance on specialized investigators and long periods of time between gun crimes, evidence collection, and evidence processing are barriers to timely intelligence. The Phoenix Police Department Crime Gun Liaison Program (CGLP) intended to close this gap by increasing the capacity of patrol officers to investigate gun-related offenses. To examine the impact of the CGLP, a randomized control trial was used to select 16 treatment and 16 matched control officers. We supplement quantitative analyses with qualitative results from focus groups. Treatment officers were referred to and responded to significantly more firearmrelated incidents, which resulted in collecting significantly more casings, firearms, fingerprints, and DNA samples during the sixmonth study period than control officers. Treatment officers also generated a significantly higher number of NIBIN leads and arrests. However, incident-level analyses provided less consistent results, though incidents involving treatment officers remained more likely to result in arrest. Qualitative results support these findings, with officers finding value in the program and reporting improved ability to respond to gun crime and reduced time spent processing scenes. Leveraging patrol officers can improve police agency capacity for responding to gun violence.