More than 60 members of four gangs in the Boston area are facing federal and state charges in a large weapons and drug bust, District Attorney Carmen M. Ortiz announced Thursday.

Forty of the 66 members have already been arrested following an overnight sting by more than 400 federal, state and local law enforcement menbers in Boston, Brockton, Chelsea and the surrounding areas. An undisclosed amount of heroin, 75 firearms and about $100,000 in cash were seized, media outlets reported.

The raid and seizures were the result of a 14-month investigation by the Bureau of Alcohol, Tobacco, Firearms and explosives into the 18th Street Gang, which spans the U.S., Mexico and Central America. 

The investigation evolved to include three other gangs that had sided with 18th Street: the East Side Money Gang in Chelsea, the Orient Heights Gang in East Boston and the Boylston Gang in Boston and Brockton.

"These individuals shot to kill and moved guns around the state freely," Ortiz said.

The investigation found members participating in significant narcotic dealing, including cocaine, crack and heroin, much of which was supplied through a network based in Brockton, NECN reported.