By Richard Valdmanis
BOSTON (Reuters) - The jury in the murder and racketeering trial of accused mob boss James "Whitey" Bulger will hear on Monday from a former FBI supervisor who admitted he and another agent used to swap secrets with the notorious Winter Hill Gang.
John Morris, who supervised the Federal Bureau of Investigation's local organized crime squad during the Winter Hill's bloody rampage in Boston in the 1970s and '80s, helped its members elude arrest and silence so-called rats, threatening to implicate them in crimes.
Prosecutors will now call him to testify against Bulger, 83, who is accused of killing or ordering the murders of 19 people while at the helm of the gang as it ran extortion and gambling rings, and settled scores.
The accused gangster's story has captured Boston's imagination for decades and inspired the Academy Award-winning 2006 film "The Departed."
On Friday, jurors got their first inside glimpse of the FBI's reported double-dealings with members of Winter Hill.
Special Agent James Marra, an investigator with the U.S. Department of Justice's Office of the Inspector General, detailed how Bulger and his associate Stephen Flemmi signed on as FBI informants in the 1970s and '80s.
Both men were overseen by FBI agent John Connolly, who has since been convicted of racketeering, obstruction of justice and murder for tipping off the gang's leaders of efforts to arrest them as well as for identifying informants.
Morris, expected to take the witness stand at the ongoing trial on Monday, was Connolly's supervisor. He was granted immunity in exchange for his testimony in 1998 federal court hearings.
Prosecutors alleged that Connolly told Bulger and Flemmi in 1982 that another Winter Hill associate, John Callahan, was being investigated in connection with another murder carried out by the gang.
Callahan later died at the hands of Winter Hill's "Executioner," John Martorano, who confessed to the killing and said Bulger ordered the hit to keep Callahan from talking.
Connolly was sentenced in 2009 to 40 years in prison for the murders, with Judge Stanford Blake saying he had "crossed over to the dark side."
Prosecutors have said Bulger fled Boston after a 1994 tip from Connolly. He eluded arrest for over 16 years before FBI officials tracked him down in June 2011, living with his girlfriend in a seaside apartment in Santa Monica, California.
If convicted, he faces the possibility of life in prison.
Prosecutors are also preparing to submit as evidence the 700-page file that the FBI developed on Bulger in the years when the agency claims he served as an informant.
Through his attorney, Bulger denied ever being an informant, insisting that he paid the corrupt FBI agent for information but never provided any of his own.
Jurors on Monday also are set to hear from Karen Smith, the daughter of Edward Connors, a Boston bar owner who was shot dead in a phone booth in 1975, allegedly because he bragged about helping the Winter Hill Gang kill another man.
Martorano has testified that Bulger and Flemmi were the gunmen in Connors' murder.
(Writing by Richard Valdmanis; editing by Barbara Goldberg, G Crosse)