The research began in 1995. The GITS data appeared to present a reasonably unbiased and complete picture of gang incidents handled by the police and that the police agencies tend to underreport rather than overreport gang incidents. In addition, the county's police training about California's legal criteria for defining gang members appears to have been successful in that police officers do not classify young people as gang members merely because of their mode of dress, ethnicity, or place of residence when they report gang incidents. Thirty-six hundred gang-related incidents were reported to the GITS database in 1994, 3,407 in 1995, 3,408 in 1996, and 3,227 in 1997. Violent crimes were the most frequent gang-related crimes, followed by vandalism/graffiti, weapons violations, property crimes, and narcotic sales. Adult street gang crime appeared to be a more serious problem than juvenile gang crime in Orange County. Furthermore, women reported more fear of gangs and gang crimes than did men, but they did not necessarily feel more at risk. Younger residents tended to rate many gang-related crimes as more serious than did older residents. Concern about community risk and disorder was a significant predictor of perceived risk and fear for almost all the crimes. Overall, the GITS project clearly demonstrates the usefulness and necessity of multijurisdictional efforts to understand, prevent, intervene, and suppress street gang activities. Tables, figures, footnotes, appended instruments, and 167 references