As the key gatekeepers of the youth justice system, police officers primarily determine the number of young persons entering the court system and offenses with which they are charged. To gauge the impact of the YOA on official youth crime and the police response to it, Uniform Crime Reports (UCR) data reported to the Canadian Centre for Justice Statistics were evaluated. Information was obtained on the number of young persons charged by police and young persons suspected and/or contacted by police. The YOA was compared to the prior Juvenile Delinquents Act (JDA) to determine if the YOA was more punitive and more effective. Researchers found no evidence in UCR data to support the popular myth that the YOA resulted in more serious youth crime in Canada. The mean rate of police-reported youth crime per 100,000 population suspected by police of offenses was about the same in 1985-1990 as in 1980-1984. This finding was true despite the addition to the youth population in most provinces and territories of young people who had been classified as adults under the JDA. Further, apart from proportionately large but absolutely very small increases in serious person offenses, the mix of police- reported youth crime did not become more serious during the decade. In fact, it became less serious as serious property offenses decreased and other offenses, such as victimless and administration of justice offenses, increased. The average national rate of young persons charged with offenses was about 20 percent higher in 1985-1990 than in 1980-1984, representing a 20-percent decrease in police diversion. The reduction in police diversion and the increase in the number and rate of persons charged represented important factors to be considered in analyzing "downstream" youth justice processes. An appendix provides information on the data analysis methods used to evaluate the impact of the YOA. 25 references, 5 notes, and 4 tables