The Philadelphia-based demonstration project was monitored from January 1975 to November 1978. Arrest records, job serarch and employment histories, and demographic and limited home-life variables for each youth were analyzed. Results show that among black teenagers, the employed engage in fewer criminal activities than do the unemployed. It is argued that search time in the legal labor market should affect both employability and criminality, since total time spent in legal and illegal labor markets is constrained. It appears that blacks view employment and crime as alternative income-generating activities, while employment status seems not to affect the criminal behavior of white male teenagers. Evidence indicates that in the group studies, whites tend to use employment as a cover for crime or to moonlight in crime. Different legitimate opportunity structures for whites and blacks can explain, in part, the behavioral differences of whites and blacks. One more important policy implication is that job opportunities targeted to high-risk black teenage populations have the additional beneficial effect of reducing crime rates. 2 footnotes, tabular data, and 36 references. (Author abstract modified)