Cocaine, especially in the form of crack, has resulted in an unprecedented wave of violence in the United States. Colombian and Mexican groups continue to smuggle cocaine to the United States at significant levels, and the result is an increase in the number of both drug distributors and drug users. In particular, gangs such as the Crips and Bloods, Dominicans, and Jamaicans are actively involved nationally in selling cocaine. These gangs are responsible for widespread cocaine-related violence. During the first 6 months of 1995, cocaine prices ranged from $10,500 to $36,000 per kilogram. The heroin market in the United States is dominated by high purity heroin from Southeast Asia. In addition, virtually all the heroin produced in Mexico is destined exclusively for distribution in the United States. South American heroin produced in Colombia is readily available in the Northeast and along the East Coast and is trafficked primarily by independent Colombian traffickers. During the first 6 months of 1995, heroin prices ranged from $100,000 to $260,000 per kilogram. Other dangerous drugs include methamphetamines, produced predominantly in the Western and Southwestern United States; LSD, with most laboratories located on the West Coast; PCP, with production centered in the Los Angeles area; and marijuana, the most readily available and widely abused drug in the United States. 2 tables