Research studies have emphasized several factors linking school experiences to adolescent crime, such as clashes of values between pupils and teachers, formation of cliques, resentment of school, and inherent conflicts between a school's institutional needs and a child's demand for attention. School is a fundamental factor in the social process by which children learn to recognize themselves and know what is expected of them. Assuming that the process of delinquency typing occurs largely in school, then delinquency rates along with joint crime committed by adolescents should be greatest during the school year. This hypothesis was tested by analyzing police force records of juvenile crime from January through December 1974 from an urban commercial center with persistent delinquency problems. The sample was confined to 203 boys who attended the town's five comprehensive schools. The crime peaks in February, March, May, and November coincided with the school terms, and the conspicuous low in August was synchronous with the summer holiday. Individual rates for burglary, theft, shoplifting, criminal damage, and traffic offenses were examined to demonstrate the influence of school on joint crime. Over 75 percent of the burglaries were committed by groups, and this crime showed the school reactive pattern by peaking in March, May, and November. In contrast, the more individualized offense of shoplifting peaked in the holiday month of April, as well as February. The crime patterns can also be attributed to the presence of more legal activities during the holidays, such as swimming pools and Youth Service programs. Boys may also be taken on trips by parents or given extra responsibilities at home when school is out. However, a comparison of home addresses and schools of boys who were involved in joint crime showed that 40 percent of the relationships were probably formed at school and about 70 percent were probably sustained through regular contacts at school. Some argue that children who are bored and angry with school vent their aggression in crimes against the community. It appears more logical to assert that a boy who is labeled delinquent at school is likely to act out this behavior during the school term.