The FBI’s Boston Field Office revealed that two Massachusetts residents have been taken into custody following an explosion at Harvard Medical School on Saturday.

Logan David Patterson, 18, and Dominick Frank Cardoza, 20, are facing charges related to the deployment of an explosive device, the FBI announced during a press briefing on Tuesday.

The arrests were executed by the FBI’s Boston Joint Terrorism Task Force, in collaboration with the Harvard University Police Department (HUPD).

During the news conference, Ted Docks, the FBI’s special agent in charge, shared details about the arrests, with U.S. Attorney Leah Foley present. The event took place in Boston on Tuesday, November 4, 2025. (AP Photo/Michael Casey)

According to an affidavit, authorities stated that the explosion was triggered by a Roman candle firework. This firework was ignited inside a wooden locker situated in a fourth-floor research lab within the Department of Neurobiology.

Video surveillance captured the pair climbing scaffolding and entering the building before the blast, officials said. 

Prosecutors said the men were visiting from Wentworth College, a nearby technical university, for Halloween social activities before the explosion.

Ted Dox, the special agent in charge of the FBI’s Boston Field Office, said that the suspects’ actions could have led to serious injuries.

“This explosive device had the potential to cause significant injury to anyone nearby — but only by sheer luck, and because of a rapid response by first responders, no lives were lost, no one was injured and property damage was limited,” Dox said. 

The FBI is investigating an explosion at Harvard Medical School. (Getty Images)

“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 shortsighted and it’s a federal crime.”

He said that the pair allegedly boasted about what they did to their friends and tried to cover up the act. Cordoza even went as far as removing his pants and tossing them in a garbage bin, Dox said, while Patterson removed his sweatshirt and sweatpants and stuffed them into his shorts, per the affidavit. 

“We believe they knew what they were doing was wrong, and they did it anyway,” he said.

“Today’s arrests should be a warning to others that if you use an explosive to maliciously damage or destroy someone else’s property, you should not be surprised when the FBI shows up at your door with our partners to take you into custody,” Dox said. 

U.S. Attorney Leah Foley for the District of Massachusetts said their actions were reckless and unlawful.

“The conduct alleged in the charging documents was not only irresponsible and risky — it was criminal — and there are consequences for those who commit federal crimes.”

Harvard University Police Department released surveillance photos of the two masked suspects fleeing the building at the time of the explosion on Saturday, Nov. 1, 2025. (Harvard University Police Department )

Dox added that investigators found no evidence of any ongoing threat to Harvard or the public.

FBI Director Kash Patel praised the coordinated operation and credited the Trump administration’s counterterrorism push for the arrests.

“President Trump’s administration has given federal law enforcement a mandate to engage with partners at every level to find bad actors and bring them to justice — and that’s exactly what we’re doing,” Patel said in a statement to Fox News Digital.

“Thank you to FBI Boston, partners at Harvard Police, and local authorities for their continued great work in this case.”

The pair appeared in federal court on Tuesday and were both charged with one count of conspiracy to damage by means of an explosive. The charge carries a maximum penalty of five years in prison and fines, prosecutors said.

The government did not seek detention. A preliminary hearing is scheduled for Nov. 24 at 10 a.m.

The explosion happened just after 2:45 a.m. Saturday in the Goldenson Building at 220 Longwood Avenue in Boston. A HUPD officer was dispatched to the scene for a fire alarm activation and witnessed two masked suspects fleeing from the building after the blast went off in a small section of the fourth-floor hallway, Harvard officials said on Sunday.

The officer tried to stop the pair before proceeding to the fourth floor and finding that an explosion had occurred.

No one was injured in the explosion, officials said.

HUPD on Saturday released surveillance photos of two suspects wearing masks and head coverings fleeing the building at the time of the blast.

The section where the explosion happened has since been cleared and is fully operational, the university said. Officials added that the building did not sustain any structural damage and all labs and equipment remained intact.

WATCH: Authorities release photo of suspect in ‘intentional’ Harvard explosion

The Boston Fire Department Arson Unit responded and made an initial assessment that the explosion appeared to be intentional, officials previously said, and they believe a single device was involved.

The university said HUPD is maintaining an increased presence on the Longwood campus as the investigation remains active and ongoing.