If you live in New England, you know the saga of reputed mobster James “Whitey” Bulger, the notorious South Boston fugitive who eluded authorities worldwide for 16 years before being captured in 2011. Now on trial for crimes including the murder of 19 people, Bulger can only hope that no one on the jury has read the Kevin Cullen-Shelley Murphy, AS’80, New York Times best-seller, Whitey Bulger: America’s Most Wanted Gangster and the Manhunt That Brought Him to Justice.

The authors, both award-winning Boston Globe journalists with their own South Boston ties, command this masterful account, noteworthy for access to Bulger’s closest collaborators and a stunning degree of detail presented for the first time. Who knew, for instance, that Bulger’s response to Boston’s forced busing was to firebomb John F. Kennedy’s birthplace and spray-paint “Bus Teddy” on the sidewalk? Who knew that when Bulger was incarcerated for armed robbery in his 20s, he volunteered to be a guinea pig in the CIA’s experiment to use LSD as a mind-control drug?

However, none of this explains why one young boy, growing up in poverty during the Depression, chose a path so dramatically different from that of another sibling, his famous politician brother, William—his hero.

Through no fault of the authors, Bulger remains an enigma even after the last page is turned. He was a man of demented and shape-shifting principles. He’d only kill fellow gangsters, until he arranged the shooting of a businessman in Oklahoma. He wouldn’t kill people if innocent civilians were in the line of fire, until he machine-gunned a crook and the neighbor who had offered him a ride home. He wouldn’t kill women until, according to people Cullen and Murphy talked to, he strangled two of them.

Yet perhaps the most shocking character in this tale is FBI agent John Connolly, the man who recruited Bulger to assist in the FBI’s national mandate to eradicate the Italian Mafia. Connolly, who is serving a 40-year sentence for helping Bulger murder a potential witness, allowed the gangster to continue his business of bookmaking, extortion, and mayhem as long as he handed over the bad guys. Bulger, in his twisted logic, considered himself a fair-minded criminal—a “good bad guy.”

Connolly received more than $235,000 from the arrangement over the years, according to Bulger’s partner in crime, Steve “The Rifleman” Flemmi. Bulger and Connolly took vacations together and exchanged Christmas presents, and Connolly demanded that his two informants be treated as “associates,” rather than criminals, in meetings with other FBI agents.

In a glaring understatement, the authors write that the FBI blurred the lines between crime and crime fighting. Connolly, for his part, downright obliterated them and drew his own warped ones in their place. Consider Connolly’s rationalization in an interview with the authors: “I don’t think they killed anyone that wasn’t trying to kill them or wasn’t going to rat them out.”

Fast-forward to 2013, when Bulger sits in the courtroom each day, watching witness after witness attest to his decades of greed, murder, and hubris. In the FBI’s mission to wipe out the Italian Mafia, Bulger, of Irish descent, was given a free ride. But as the trial winds down, it seems clear there will be no more Get Out of Jail Free cards for Whitey Bulger.

Joan Lynch is managing editor.