Violence committed by and against juveniles was the focus of this study. Two groups were examined: incarcerated (criminally active) juveniles and students in inner-city high schools, since these youths are popularly considered to engage in and experience violence (especially gun-related violence), to belong to urban street gangs, and to participate in the drug trafficking thought to lead to excessive gun violence. Self-administered questionnaires were completed by 835 male inmates in six correctional facilities and 1,663 male and female students from ten inner-city high schools in California, Illinois, Louisiana, and New Jersey. Data collection took place during January through April of 1991. To maximize response rates, inducements of five dollars were offered to the inmates, Spanish-language versions of the questionnaire were provided to inmates who preferred them, and personal interviews were conducted with inmates whose reading skills were less than sufficient to complete the questionnaire on their own. In four schools, principals permitted the inducements to be offered to students to participate in the study. As with the inmate survey, a Spanish-language version of the questionnaire was provided to students who preferred it. The questionnaires covered roughly the same core topics for both inmates and students. Items included questions on sociodemographic characteristics, school experiences, gun ownership, gun use for several types of firearms, gun acquisition patterns, gun-carrying habits, use of other weapons, gang membership and gang activities, self-reported criminal histories, victimization patterns, drug use, alcohol use, and attitudes concerning guns, crime, and violence. In both questionnaires, the majority of the items covered firearms knowledge, acquisition, and use. The remaining items in the inmate survey primarily covered criminal behavior and, secondarily, victimization histories. In the student survey, these priorities were reversed.