The two Massachusetts men who were accused of setting off a large commercial firework inside a Harvard Medical School laboratory in November pleaded guilty in federal court in Boston on Friday.
Logan David Patterson, 18, and Dominick Frank Cardoza, 21, each pleaded guilty to one count of conspiracy to damage by means of an explosive, the U.S. Attorney’s Office for the District of Massachusetts said in a news release.
The incident, which occurred around 2:45 a.m. on Nov. 1, damaged part of Harvard Medical School’s Goldenson Building, which houses a research lab in the school’s neurology department.
The firework was detonated from inside a wooden locker on the laboratory’s fourth floor. The blast set off a fire alarm, and as a campus police officer responded, two people fled the building.
Surveillance cameras captured the two men, later identified as Mr. Patterson and Mr. Cardoza, wearing dark clothing and face coverings. They were walking toward campus and lighting what appeared to be Roman candle fireworks, according to charging documents.
Additional security footage recorded them visiting the fifth floor of the building, leaving through a first-floor emergency exit and fleeing in opposite directions, the U.S. Attorney’s Office said. They removed and discarded clothing items and returned to the nearby Wentworth Institute of Technology, where they were visiting for Halloween.
There was no structural damage to the building, Harvard officials said at the time, but the explosion did affect a small section of hallway on the fourth floor.
Mr. Patterson, of Plymouth, Mass., and Mr. Cardoza, of Bourne, Mass., both agreed to a plea deal, according to court documents.
The charge that both men pleaded guilty to is punishable by a sentence of up to five years in prison, three years of supervised release and a fine of up to $250,000. Sentencing is scheduled for August.

