The FBI has just released its National Gang Threat Assessment 2009, which estimates that there are “approximately 1 million gang members belonging to more than 20,000 gangs” in the US as of September 2008. Among this year’s trends:

Gang members are migrating from urban to suburban and rural areas, expanding the gangs’ influence in most regions. They are doing so for a variety of reasons, including expanding drug distribution territories, increasing illicit revenue, recruiting new members, hiding from law enforcement, and escaping from other gangs…

According to the report, “approximately 640 gangs with more than 17,250 members are criminally active in the New England region.” The “most signficant” gangs here are the Hells Angels, Latin Kings, Outlaws, Tiny Rascal Gangster Crips, and the United Blood Nation. And here’s a slippery statistic: “Gangs are responsible for as much as 60 percent of the crime in some communities” in New England.

Chicago appears to have the worst situation, thanks to an influx of “West Coast-based Hispanic gangs.” Curiously, Boston is one of the few big cities whose police department is not listed among the sources for the FBI report. The Boston field offices of the FBI and DEA are credited instead.

CommonWealth magazine reported on gang activity on the North Shore last year, in a story by Jay Atkinson.