Jeremiah T. O'Sullivan (died 2009) was a Boston-based federal prosecutor for the United States Department of Justice at a time when FBI agents collaborated with Winter Hill Gang leader James "Whitey" Bulger.
Bulger and his right-hand man Steve Flemmi were originally going to be part of this indictment, but Federal Bureau of Investigation (FBI) agent John Connolly and his supervisor John Morris were able to persuade O'Sullivan to drop the charges against them at the last minute.
[7] In 1998, O'Sullivan suffered a heart attack and several strokes after being asked to testify about Bulger and Flemmi.
[1] Five years later,[2] O'Sullivan spoke in front of Congress during the Committee on Government Reform's investigation of the FBI's Boston branch.
He stated that he knew some informants were committing murder and that they had relationships with FBI, but O'Sullivan said he did not act upon the situation because he was "intimidated by the bureau".