Two Donald Trump supporters who stormed the U.S. Capitol on Jan. 6 while wearing costume attire received federal prison sentences Friday, the same day prosecutors secured a string of guilty pleas from other rioters.

Aaron Mostofsky, a 35-year-old man who was dressed as a caveman when he stormed the Capitol, was sentenced to eight months behind bars followed by a year of supervised release.

The Brooklyn resident, whose father is a judge in Kings County Supreme Court in New York, pleaded guilty in February to a felony charge of civil disorder and misdemeanor charges of theft and entering a restricted building. Video showed Mostofsky joining others pushing against a police line outside the Capitol on Jan. 6, and that he was roughly the 12th person to enter into the building after rioters smashed windows to gain entry.

Mostofsky, who had told a friend his costume was meant to illustrate his belief that “even a caveman” knew the 2020 election was stolen, said Friday he was “sorry for the officers that had to deal with that chaos,” the Associated Press reported.

U.S. District Judge James Boasberg said Mostofsky was “on the front lines” of the Capitol siege, which the judge said “imposed an indelible stain on how our nation is perceived,” according to the AP.

Nathan Entrekin, a 49-year-old Arizona man who wore a gladiator costume to portray Captain Moroni from the Book of Mormon, was sentenced to 45 days in prison and three years of probation. Judge Florence Y. Pan said that the gravity of Jan. 6 “cannot be overstated,” and that the mob stormed the building to “subvert the will of the American people, and to essentially overthrow the democratically elected government.”

An image from a video Entrekin filmed inside the Capitol, included in the Justice Department’s sentencing memo, showed how rioters trashed the Senate Parliamentarian’s office on what Pan called “that dark day.”