AbstractIn this article, we examine gang membership and gang activity in Dona Ana County, New Mexico. We collected the data through a self‐administered questionnaire completed by 373 randomly selected 9th and 11th grade students attending two high schools and two junior high schools. By the self‐report method, 56 indicated they were currently active in a gang; another 45 had been members of gangs but were no longer involved; and, “wannabes,” or students who at some time had considered joining a gang but did not or could not, totaled 68. The 169 students who indicated some interest in or involvement with gangs represented 45% of the total sample. A more restrictive definition of actual gang membership (i.e., the group must have initiation rites and employ some external symbols of membership, such as “colors,” tattoos, or handsigns) results in a different trichotomization. We employ both the self‐definition and restrictive definition of gang membership in our analysis of their personal biographical characteristics and criminal behavior. Our findings suggest that self‐definition demonstrates clearer ties to self‐reported gang‐related activities than does the more restrictive one. We discuss the policy implications of this fin