The present study primarily focused on the appraisals that nearly 4000 middle school and high school students made of crimes or unlawful acts they hypothetically witnessed. The key appraisal dimensions were concerned with students' evaluation of the legality and acceptability of the crimes and unlawful acts, and with the evaluation of the personal concerns, emotional consequences for the self, and potential benefits for the victims that would accrue from filing and not filing a police report for the crimes. Students also evaluated the probability of filing a police report, if the situation actually occurred. The primary goal of the study was to examine the general hypothesis that adolescents' willingness to file a police report would be directly affected by their appraisals. It was also hypothesized that these appraisals, in turn, would mediate any effect exerted by adolescents' personal levels of antisocial or aggressive behaviors and prosocial behavior, as well as by their personal views about socially accepted codes of conduct. The findings of structural equation modeling confirmed the tenets of these guiding hypotheses.