the previous analysis indicates that gang membership facilitates a broad range of delinquent behaviors including violence, drug use, and drug sales. When boys join gangs their delinquency increases and when they leave gangs their delinquency decreases. Here we focus on a related form of illegal behavior: owning and carrying illegal firearms. In particular, we are interested in the interplay between gang membership and patterns of owning and carrying guns. There are three general analytic questions. First, do gangs recruit those who carry illegal guns prior to gang membership, does gang membership enhance gun carrying, or are both processes at work? Second, do former gang members continue carrying guns as a result of their gang experience? Finally, what is the joint impact of gang membership and gun involvement on delinquency, drug use, and drug sales? Because research has shown that illegal gun carriers are more active in criminal activity (Lizotte et al., 2000) and that gang members show higher levels of criminal activity (Chapter 6), we hypothesize that gang members who also carry guns will have higher levels of criminal activity than one would predict from either factor alone. We conduct all these analyses for two types of illegal gun carriers: those who carry illegal guns but do not own them, and those who carry illegal guns that they own. The distinction is important, especially at these ages and especially for gang members.