Stephen Joseph Flemmi is an American gangster and convicted murderer and was a close associate of Winter Hill Gang boss Whitey Bulger. Beginning in 1975, Flemmi was a top echelon informant for the Federal Bureau of Investigation (FBI).
Flemmi in 1965
FBI surveillance photograph of Flemmi (left) with Winter Hill Gang boss, James Bulger (right), in 1980
The Winter Hill Gang was a loose confederation of organized crime figures in the Boston, Massachusetts, area. It is generally considered an Irish Mob organization, with most gang members and the leadership consisting predominantly of Irish-Americans, though some notable members, such as Johnny Martorano, are of Italian-American descent.
FBI surveillance photograph of the former Winter Hill Gang hierarchy in the 1980s. Mob boss James "Whitey" Bulger (right) and lieutenant Stephen Flemmi.