• New Yorker Aaron Mostofsky, who broke into the Capitol during the Jan. 6 riot while dressed as a caveman, pleaded guilty to a felony civil disorder charge, the Department of Justice said.
• Mostofsky also pleaded guilty to misdemeanor charges of stealing government property and entering and remaining in a restricted building, the DOJ said.
• The Capitol was stormed by hundreds of former President Donald Trump's supporters, spurred by false claims about election fraud. They temporarily stopped Congress from confirming President Joe Biden Electoral College victory.
• Mostofsky said he was dressed as a caveman to make the point that "the fraud in the 2020 Presidential Election was so obvious, even a caveman would know the election was stolen," according to the DOJ.

A Brooklyn man who clashed with police, snatched officers' gear and broke into the Capitol during the Jan. 6 riot — all while dressed as a caveman — pleaded guilty to a felony civil disorder charge, the Department of Justice said Wednesday.

The man, 35-year-old Aaron Mostofsky, the son of a New York judge, also pleaded guilty in federal district court in Washington, D.C., to misdemeanor charges of stealing government property and entering and remaining in a restricted building, the Justice Department said in a press release.

He faces a maximum sentence of five years behind bars and a hefty fine for the felony charge alone, the DOJ said, though his final sentence may be lower. Mostofsky's plea agreement notes that his lawyer and prosecutors agree that federal sentencing guidelines would recommend he get a prison term within the range of one year to 18 months.

The judge in Mostofsky's case, however, also could sentence him below or above that range.

Hundreds of former President Donald Trump's supporters stormed the Capitol on Jan. 6, 2021, forcing lawmakers to flee their chambers and temporarily blocking the process of transferring power to President Joe Biden, who won the 2020 presidential election. Many of the rioters were spurred by Trump's false assertion that the election had been stolen from him through widespread fraud.

On the day of the attack, Mostofsky had traveled by bus to Capitol Hill from New York City and had posted "DC bound stopthesteal" en route, according to a DOJ court filing stating his offense.

He was dressed as a caveman and carrying a walking stick, explaining to a friend at one point that "the fraud in the 2020 Presidential Election was so obvious, even a caveman would know the election was stolen," the DOJ said.

Shortly before 1 p.m., Mostofsky joined a group of rioters trying to force through a police line outside the Capitol. "Mostofsky used his weight and strength in the effort to break the police line," the DOJ said.

As he made his way up toward the entrance to the Senate wing, Mostofsky picked up and put on a U.S. Capitol Police bullet-proof vest. He then entered the building through a door that other rioters had busted open from the inside, the DOJ said.

Once inside, Mostofsky quickly grabbed an officer's riot shield, then joined the mob at a staircase "where they pursued a U.S. Capitol Police Officer upstairs" to a corridor outside the Senate chamber, according to the DOJ.

Mostofsky gave an interview to a reporter before leaving the Capitol around 2:36 p.m. He was "stripped of the shield" by a Capitol police officer as he left, the DOJ said.

Mostofsky is set to be sentenced on May 6. He faces up to five years in prison and a fine of $250,000 for the charge of felony civil disorder. Each of the misdemeanor charges carry a maximum one-year prison term and a $100,000 fine.

More than 725 individuals in almost every state in the U.S. have now been charged with crimes related to the riot. More than 225 of those people have been charged with assaulting or impeding law enforcement.

Mostofsky's plea adds to the more than 165 people who have now pleaded guilty to federal charges stemming from the attack. The DOJ continues to investigate.