John Martorano was born in Somerville, Massachusetts, in 1940. He is the older brother of James Martorano by eleven months. His father was an immigrant from Riesi, Sicily. He was raised Catholic and served as an altar boy.
The Martorano family moved to the Irish enclave of East Milton. John attended Thayer Academy in Braintree with his brother Jimmie in grades 6 and 7. He later enrolled in Mount Saint Charles Academy in Woonsocket, Rhode Island, from which he graduated. During high school, he played football with future CBS News television journalist Ed Bradley, whom he affectionately referred to as "Big Ed". Earlier, he had been a grammar school classmate of future congressman Bill Delahunt.
In a 60 Minutes interview with Steve Kroft he claimed that when he was young his father told him, "You're the oldest son and this is your heritage" (referring to his father's connections to organized crime). "You've got to take care of your family and be a man."
After graduating from high school, Martorano turned down seven football scholarships and instead stayed in Boston. Hanging out in the Combat Zone, Martorano fell under the guidance of Stephen Flemmi, and by the age of twenty-five had become a professional mobster. He committed his first murder at 24, when he allegedly killed Patriarca crime family made man Robert S. Palladino, who was going to testify in a case involving the murder of prostitute Barbara Sylvester in his father's restaurant.
Ralph DeMasi, a Boston mobster incarcerated in White Deer, Pennsylvania, would later write to the courts that when he was driving down Morrissey Boulevard with fellow Irish mobster William (Billy) O'Brien in 1964, Martorano pulled up in a car alongside them and gunned down O'Brien, shooting him seventeen times with a machine gun and wounding DeMasi. In his letter about the events that almost led to his death he wrote, "I thought someone was taking target practice at us. It was my good friend John Martorano."
Martorano rapidly became one of the Winter Hill Gang's most prolific enforcers under the tenures of Howie Winter and Whitey Bulger. In January 1968, after Hubert "Smitty" Smith, an African-American male, helped mobsters Rocco Lammattina and John Cincotti beat up Flemmi in an after-hours saloon, Martorano tracked the man to a car on Normandy Street in Dorchester. As it happened, Smith was accompanied by a nineteen-year-old woman, Elizabeth Frances "Liz" Dixon, and a seventeen-year-old boy, Douglas Barrett. Martorano walked up to the car and killed all three occupants with his .38-caliber snubnosed revolver. Martorano was ignorant of the circumstances behind the beating of Flemmi when he confronted Smith at the saloon the night after the beating - "He (Smith) kept giving me the wrong answers. He didn't give me any respect. All he had to say was 'I didn't know he was your friend, I'm sorry.' That's all he needed to say." As a result of this, Martorano was facetiously called "Sickle Cell Anemia" by his fellow gangsters.
In 1979, Flemmi and Bulger learned that Martorano and several other Winter Hill members were about to be indicted for a horse race-fixing scheme involving Fat Tony Ciulla. They warned Martorano, who quickly fled to Florida. He spent the next 16 years as a fugitive, though he was frequently called on to take part in murders. Along with Winter Hill member Joe McDonald, he was the triggerman for the hits on Roger Wheeler and John Callahan.
Arrested in 1995, Martorano was charged, along with Flemmi and two Boston mafiosi, on a massive racketeering indictment; however, he abruptly agreed to a plea bargain deal in 1999. He was angered that Bulger and Flemmi hadn't made any effort to keep him out of the 1979 race-fixing indictment, but had persuaded corrupt FBI agent John Connolly to ensure they wouldn't be indicted. More seriously, Bulger and Flemmi had been the ones to tip off authorities about his whereabouts. In return for confessing his murders, Martorano received a reduced prison sentence of 12 years. In 2007, he was released from prison and given $20,000 to start a new life.Alfredo (Indian Al) Angeli (Now called "Native American Al")
Joseph J. "Indian Joe" Notarangelli
James "Spike" O'Toole
Herbert "Smitty" Smith
On January 15, 2008, Martorano was interviewed by Steve Kroft on the CBS News television program 60 Minutes. Initially Martorano had agreed to have his friend Ed Bradley interview him, but Bradley died before this could occur. During the interview, Martorano expressed remorse for killing Elizabeth Dickson, the woman in the car in Dorchester.
Although his friends Whitey Bulger and Stephen Flemmi are considered by many criminologists and investigators to be serial killers, Martorano told Bradley, "I might be a vigilante, but not a serial killer. Serial killers, you have to stop them. They'll never stop, they enjoy it. I never enjoyed it. I don't enjoy risking my life but if the cause was right, I would."
In June 2013, John Martorano testified as a prosecution witness in the Whitey Bulger trial in Boston, Massachusetts.
Martorano was married to Carolyn Wood, an Irish-American, with whom he fathered a son, John Martorano, Jr., and a daughter, Jeannie. Carolyn divorced him in 1975.