Police in widely different settings base their judgments on "street" experience and similar theories of delinquency causation linking social class background, parental neglect, and delinquent Behavior. They see lower-class boys as more likely to be involved in delinquent conduct than boys with other family and social class backgrounds. It is shown that officers predictions for individual boys prove to be inaccurate, measured by official contact records over a six year period. (Author)