In-car camera technology for police vehicles has proliferated over the past decade, enabling both the safety of officers and suspects to be improved. Although many law enforcement agencies consider their in-car cameras to be among their most frequently used and important technology within their agencies, there have been no comprehensive studies on the impact of in-car cameras on officer conduct, management of law enforcement agencies, and the public’s perceptions of the police. The current report presents the results of two studies on the impact of in-car cameras. The first study was a process evaluation that assessed the selection, acquisition, installation, and deployment of in-car camera technology among law enforcement agencies. The second study was a field evaluation that measured the impact of in-car cameras on eight variables: officer safety, officer performance and professionalism, agency liability and internal control, training and education, community perception, agency policies and procedures, agency leadership, and the judicial process. The findings of the process evaluation indicated extremely positive outcomes of the grants program offered by the Office of Community Oriented Policing Services (COPS) to purchase in-car cameras; 91 such grants were awarded to 50 agencies in 2003. Agencies that received COPS grant funding were effective at rapidly acquiring and installing the in-car camera technology. Findings from the impact evaluation indicated positive outcomes across all eight study variables as a result of in-car camera use. Specifically, officer safety was enhanced, agency accountability was improved, and agency liability was reduced, among other positive outcomes. Lessons learned included the need to carefully plan in-car camera use policies that include the storing, filing, and retrieving of video evidence. Guidelines for best practices are presented for topics such as assessing the video evidence needs of agencies and managing video evidence. Figures, appendixes