BOSTON (AP) — The attorney for James “Whitey” Bulger said Monday that the former Boston mob boss and one-time FBI informant shouldn’t be prosecuted in 19 murders because the government promised him immunity for past or future crimes.

Attorney J.W. Carney Jr. said he’d soon file a motion to dismiss the charges because “a representative of the federal government” gave Bulger the blanket immunity during the 1970s.