CAMBRIDGE, Mass. — A New Hampshire man accused of participating in a plot in which a caller issued bomb threats last year to Harvard University and demanded a large amount of bitcoin was sentenced Thursday to three years of probation.

The threats caused the evacuation of Harvard's Science Center Plaza and surrounding academic buildings, and the controlled detonation of what was later determined to be a hoax device on April 13, 2023, according to prosecutors.

William Giordani, 55, was arrested last year on charges including making an extortionate bomb threat. That charge was dropped, and he pleaded guilty to one count of concealing a federal felony, effectively knowing about a felony and not reporting it, according to his lawyer.

Giordani had faced a sentence of up to three years and a fine of up to $250,000. Prosecutors instead recommended a sentence of up to three years' probation.

Prosecutors said at the time that they agreed to accept Giordani's guilty plea in part because they believed he had been pulled into the plot after he responded to a Craigslist ad. They also said they believed his response to the ad was driven in part by a drug habit and that he has made efforts to remain in a recovery program.

The case stems from an episode last April when Harvard University's police department received a warning from a caller electronically disguising their voice saying bombs had been placed on campus.

The caller demanded an unspecified amount in Bitcoin to prevent the remote detonation of the bombs, prosecutors said. Only one hoax device was discovered.

Investigators said Giordani responded to the Craigslist ad looking for someone to purchase fireworks in New Hampshire and pick up some other items in Massachusetts — including wire, a metal locking safe and a bag — and deliver the items to his son at Harvard.

After Giordani collected the items, the individual said his son was unable to meet him and he should leave the bag with the items on a bench in a science plaza area at the school. Police later destroyed those items.

Investigators said that at some point Giordani began to harbor suspicions that the items could be used to construct a bomb, pointing to deleted text messages where he acknowledged it could be bomb material. In another text to his girlfriend, Giordani said, ''I got scammed,'' police said.

Giordani also took steps to hide from police after they made attempts to reach him in order not to reveal his role in delivering the bag, investigators said.

There were no injuries.