2 Massachusetts men are arrested in the weekend explosion at Harvard Medical School

BOSTON (AP) — Two Massachusetts men were arrested Tuesday in connection with a weekend explosion at Harvard Medical School, authorities said.

Logan David Patterson and Dominick Frank Cardoza face charges of conspiracy to damage by means of fire or an explosive, according to the charging document. Patterson, an 18-year-old from Plymouth, and Cardoza, a 20-year-old from Bourne, were arrested Tuesday morning and were due to be arraigned in federal court later in the day.

The explosion occurred early Saturday on the fourth floor of Harvard Medical School’s Goldenson Building, which houses labs and offices associated with the school’s neurobiology department. No one was injured.

“Anxiety levels naturally rise when the public learns that an explosion was intentionally caused. I would say those levels may rise even higher in the Boston area,” U.S. Attorney Leah B. Foley said at a news conference, noting that the investigation is ongoing but that there’s no further threat to the university.

According to the charging document, witnesses said the men were visiting Wentworth College for Halloween activities, including parties at area schools. On the day of the blast, surveillance footage captured the two walking toward Harvard’s medical school. Witnesses said the pair chose the building because it looked abandoned and got into it via the roof, the charging document states.

Witnesses said the pair lit a roman candle outside of the building and placed a cherry bomb inside of a locker in the building that then exploded, according to the charging document.

“Let me be clear: Setting off an explosive device inside a locker at an institution geared toward higher education is not some harmless college prank. It’s selfish, it’s short-sighted, and it’s a federal crime,” said Ted Docks, the FBI’s special agent in charge.

Neither Foley nor Docks would speculate as to the motive.

Medical school officials said the explosion caused no structural damage and that all labs and equipment remained intact. The Boston Fire Department determined that the explosion was intentional. Police said officers did not find additional devices during a sweep of the building.

An officer who responded to a fire alarm that morning encountered two people running from the building, university police said.