The NEW-ADAM program was a 3-year, rolling program of surveys that involved 16 police pretrial custody sites in England and Wales conducted during 1999 to 2002. Eight custody sites were surveyed in the first year of the program, and eight additional sites were surveyed in the second year of the program. In the third year, the first eight sites were revisited. Arrestees were selected for interviews over a 24-hour period for 7 days a week during the survey period. The primary method of data collection was a personal interview that used a structured questionnaire, which included questions on self-report drug use, crime, legal and illegal sources of income, the amount of money spent on drugs, and treatment needs. The follow-up questionnaires included questions on drug markets, sources of drug supply, the use of weapons, and ownership of guns. In 14 of the 16 locations, arrestees were also asked about gang membership. A total of 2,725 arrestees were interviewed. The findings indicate that 15 percent of the arrestees had either current or past experience as a gang member; 4 percent of arrestees interviewed reported that they were currently members of a gang, and 11 percent reported they had been members of a gang in the past. Gang members (current and past) were more likely than nongang members to report committing one or more of each of the property crimes listed in the questionnaire in the last 12 months; however, current gang members were only different from nongang members in the commission of auto theft and the handling of stolen goods. Gang members were significantly more likely than nongang members to have committed robbery. Gang members were also more heavily involved in the possession of weapons and guns. Overall, the findings from this study are consistent with the characteristics of street gangs found in U.S. research. Although it is too early to begin applying gang theory to the apparent developments in gang membership in the United Kingdom, this study provides some evidence that the formation of gangs is increasing, and these gangs are involved in criminal behavior and drug offenses. 5 tables and 30 references