The two men who caused a small explosion inside a Harvard Medical School building last Halloween avoided jail time Thursday, as a federal judge sentenced each to three years of probation.
Logan David Patterson, 19, of Plymouth, and Dominick Frank Cardoza, 21, of Bourne, were also ordered to perform roughly 300 hours of community service and jointly pay $28,517 in restitution for damage caused by the explosion.
US District Court Judge Angel Kelley declined prosecutors’ request that the first six months of their probation be served in home confinement.
“I believe the harsh consequences that flowed from this conviction are a sufficient deterrent,” Kelley said.
Both men pleaded guilty in April to conspiracy to damage a building by means of fire and an explosive.
No one was injured in the blast, which damaged the fourth floor of the medical school’s Goldenson Building in Boston’s Longwood area during the predawn hours of Nov. 1, 2025, after the pair had been at multiple Halloween parties with friends.
Along with probation, community service, and restitution, Patterson and Cardoza were ordered to write letters apologizing to Harvard.
Patterson also apologized in court.
“This was a very serious act,” Patterson said. “At the time, I thought my actions were harmless and they turned out to be much bigger.”
Prosecutors had recommended three years of probation, with the first six months on home confinement. In sentencing papers, they acknowledged the defendants’ youth while emphasizing the seriousness of what they did.
“The defendant committed a serious offense, even if that offense was motivated by immaturity and revelry rather than more serious intentions to cause damage or fear,” prosecutors wrote.
Outside court, Stefan Rozembersky, a lawyer for Cardoza, called the sentence fair and stressed that neither man had a criminal record.
“This was not a terrorist attack. This was not a coordinated attack against the government or aimed at Harvard; this was a couple of kids with firecrackers, not even bombs,” Rozembersky said, calling it “mischief that went way out of control.”
But he said the felony convictions would continue to carry serious consequences for the men.
“It’s not without severity,” he said. “Having this felony record is going keep them from having some things in life and harm them for a long time.”
The break-in and explosion prompted a massive emergency response and unnerved the elite campus, home to cutting-edge medical research.
The blast caused little property damage but drew national attention given the contemporary political climate, particularly at elite universities such as Harvard, which the Trump administration has accused of fostering a climate of antisemitism, a charge the Ivy League institution has adamantly and resolutely denied.
According to an FBI affidavit, the pair arrived at Wentworth Institute of Technology around 8 p.m., meeting up with several people who were going out for Halloween festivities.
Cameras began to record them in Longwood after 2 a.m., and they were seen walking toward the medical school campus at 2:23 a.m.
At 2:24 a.m., they set off what appeared to be Roman candle fireworks outside, footage showed.
A few minutes later, video footage from the Goldenson Building shows them climbing a chain-link fence and hopping into a construction area, the affidavit said. At 2:36 a.m., they’re spotted climbing scaffolding next to the building and getting onto the roof.
At 2:45 a.m., police received an alert that there had been an explosion on the fourth floor of the building, which houses a research laboratory that focuses on neurobiology.
They soon left the building, fleeing in opposite directions, according to video footage.
A message was sent to Harvard officials seeking comment Thursday night.
Material from the Associated Press and previous Globe coverage was used in this report.
Travis Andersen can be reached at travis.andersen@globe.com.