As South Boston erupted in violence in the early days of court-ordered school desegregation in the mid-1970s, the hometown gangster James "Whitey" Bulger went on a personal rampage, firebombing the Brookline birthplace of President John F. Kennedy and torching a school that stood near the home of the judge who had ordered busing, according to a close Bulger associate.

Several days before US District Judge W. Arthur Garrity's plan to integrate Boston's schools went into effect in September 1974, Bulger and an accomplice set a blaze at an elementary school in the judge's Wellesley Hills neighborhood, according to the source, who spoke on condition of anonymity.

"That was an attack on Garrity," said the source, whose association with Bulger spanned more than three decades.

A year later, on Sept. 8, 1975, the first day of school in the second tumultuous year of court-ordered busing, Bulger and an unidentified cohort hurled a Molotov cocktail through the back-door window of Kennedy's birthplace, in retaliation for Senator Edward M. Kennedy's outspoken support for school desegregation, the source said.

Bulger, according to the source, fled the scene after spray-painting "Bus Teddy" in black on the sidewalk outside the national historic site.

"He was all rah-rah-rah about fighting busing," the source said of Bulger, who he said was furious at Garrity for forcing South Boston children to attend schools outside their neighborhood while black children were being bused in.

"He wanted to make a point. He liked to say he was doing something active to fight busing," the source said. "He was and is a racist."

While Bulger is charged with killing 19 people, including two women, from 1974 to 1985, as well as with extortion, drug trafficking, and money laundering, this is the first time he has been linked to busing violence in connection with busing.

Bulger never surfaced as a suspect in the blaze that caused about $30,000 in damage to Kennedy's birthplace, closing it for three months. Nor was he suspected of setting fire to the former Kingsbury Elementary School in Wellesley Hills, according to fire officials.

Both fires were determined to have been set, and the arson appeared to have been driven by antibusing sentiments, officials said at the time.

The fire at the school destroyed two classrooms and forced students to be temporarily bused to another school.

A Wellesley Fire Department lieutenant, Joseph Keough, who was among the firefighters who put out the fire on Sept. 11, 1974, at the school, said gasoline had been used to set it. He said officials believed the school had been targeted because it was in the neighborhood where Garrity lived.

The day after the fire, a man called the fire station claiming responsibility for the fire, and vowed to burn down every school in town over 30 years, Keough said.