The evaluation focused on how OC was adopted and implemented by the Baltimore County Police Department and the impact of OC use on police and suspect injuries and complaints about police brutality, as well as its effectiveness in subduing uncooperative or physically resistant individuals. Data collection for both the impact and process evaluations began in mid-July 1993. Findings revealed that the police used the spray 194 times on humans or dogs in a 9-month period, mainly for battery, assault, disorderly conduct, domestic assault, mental, and traffic-related cases. In 90 percent of the incidents the individual was sufficiently incapacitated to permit arrest or other officer actions. The total number of citizen complaints alleging force was lower during the period when spray was used than in the two periods before the spray was used. The process evaluation revealed that the police agency used a phase-in approach to training, developed a standard operating procedure, and addressed issues related to police use of force. Tables, figures, footnotes, and appended background information and program documents from the police agency