Does arresting juveniles deter or promote future offending, and how does it affect the chances of future arrests? These questions were studied through official arrest data and self-reported offending data from the Project on Human Development in Chicago Neighborhoods, using propensity score methods. First arrests increased subsequent offending and subsequent arrest through separate processes, and the effects on rearrest were substantially larger. Being labelled as an arrestee seems to trigger "secondary sanctioning" processes beyond any effects on offending. Attempts to ameliorate deleterious "labeling" effects should include efforts to dampen their escalating punitive effects on societal responses.