Gerard M. O’Neill, an investigative reporter and editor for The Boston Globe whose exposés included the revelation that James (Whitey) Bulger , Boston’s notorious crime boss, was an informant for the F.B.I., died on Thursday at his home in Boston. He was 76.

The cause was interstitial lung disease, his son Shane said.

Mr. O’Neill, who spent 35 years at The Globe, was one of three original reporters on the paper’s Spotlight Team , the full-time investigative strike force that was modeled after the Insight Team of The Sunday Times of London.

Two years after its founding in 1970, Spotlight — with the 29-year-old Mr. O’Neill on the team — won a Pulitzer Prize for its first major investigation, which uncovered rampant corruption in Somerville, a Boston suburb.

Later, as chief of the unit, Mr. O’Neill would help report, write and edit investigations that swept numerous awards, landed multiple Massachusetts officials in jail and led to reforms.