During the past decade, law enforcement officials throughout the United States have addressed the growing problem of organized criminal groups. Five of these groups have been identified by authorities as posing particular problems for law enforcement. These groups have evolved into sophisticated criminal organizations through drug trafficking. These five groups, Columbian drug traffickers, Jamaican posses, Chinese organized crime, Vietnamese gangs, and Los Angeles street gangs are discussed in terms of their criminal histories, composition and organizational structures, drug trafficking activities, laundering networks, and criminal activities. Major investigations of these five criminal groups are discussed. In addition, information obtained from interviews with law enforcement officials relate problems and obstacles which prevent them from investigating and prosecuting members of nontraditional organized criminal gangs. Other subjects broached by the officers include gun control, adequacy of current legislation, enforcement of immigration laws, juvenile justice reform, prison overcrowding, and tracking gang activity.