The project aimed to conduct the first experimental evaluation of hotspot policing in Brazil, structured as a randomized controlled trial. The initiative was led by the Inter-American Development Bank (IDB) in partnership with the Paraná Military Police and the State Public Security Secretariat. During the study, 422 street segments with high robbery incidence were identified, mapped using georeferenced data and advanced spatial analyses. Half of these segments were randomly selected to receive additional patrolling for three months, while the other half served as a control group to measure the project’s impact.

The experiment resulted in an average increase of 15 minutes in the treated segments compared to the control group, as measured using GPS data. Evaluation data indicated a 22% reduction in robberies in patrolled areas on weekdays compared to the control group, with no evidence of crime displacement to neighboring segments. However, an increase in thefts was observed in the treated segments, possibly due to changes in offender behavior or police recording practices. Additionally, the analysis showed that the positive effects on robberies persisted for up to three months after the experiment ended but disappeared afterward, highlighting the importance of maintaining continuous, data-driven policing strategies to sustain results. The project also provided a practical opportunity for impact evaluation training for the Paraná Military Police and for using GPS data to monitor police allocation.