Former NYPD officer Thomas Webster sentenced to 10 years for storming Capitol on Jan. 6

A federal judge has sentenced former New York Police Department officer Thomas Webster to 10 years in prison for assaulting officers outside the Capitol during the Jan. 6 riot.

The sentence is the longest prison term yet for a defendant in the Justice Department's criminal investigation of Jan. 6, but short of the 17.5 years prosecutors had sought for Webster.

The DOJ had previously released harrowing officer body camera footage that showed Webster, 56, assaulting law enforcement.

The sentencing in D.C. court comes after a jury found Webster guilty on six charges, including assaulting a police officer, in May.

Webster was found guilty of assaulting D.C. Metropolitan Police Department officer Noah Rathbun, who testified during the trial.

According to testimony and video of the riot, Webster, clad in a bulletproof vest and waving a Marine Corps flag, pushed toward the front of the crowd and yelled at Rathburn to "take your s--- off!"

Video shows Webster swing a metal flagpole and breaking apart bike racks that were acting as a police perimeter. As Rathbun backed away, Webster tackled him and then pulled at the officer's gas mask. Rathbun testified that he began to choke on his chin strap as Webster pulled at the mask. Video shows that Rathbun hit Webster's face while trying to push him away.

During the trial, Webster claimed that Rathbun had provoked the fight and that he pulled at Rathbun's mask as a form of self-defense.

Webster was convicted of assaulting, resisting or impeding an officer using a dangerous weapon; civil disorder; entering and remaining in restricted grounds with a dangerous weapon; engaging in physical violence in restricted grounds with a dangerous weapon; and engaging in an act of physical violence on Capitol grounds.

During his sentencing, Webster was given three years of supervised probation and ordered to pay $2,060 in restitution.

Judge Amit Mehta chose to apply a 4-level enhancement because Webster was wearing body armor. This alone added 30 months to the minimum sentence he could have received.

Mehta described Webster as an ordinary American, a public servant in the NYPD and the Marine Corps, who "lost everything in a split second."

While making a statement during his sentencing hearing, Webster wept, saying he should have never come to D.C. on Jan. 6. He said he was overwhelmed and frustrated by his emotions and political rhetoric and should have known to turn away but did not have the courage to do so. He also apologized to Rathbun.

Webster, of the village of Florida, New York, served in the Marine Corps from 1985 to 1989 and as an NYPD officer from 1991 to 2011.

"As a former Marine and retired police officer, Thomas Webster could readily see the growing dangers to law enforcement when he and other members of the mob targeted the Capitol on January 6th," U.S. Attorney Matthew M. Graves said in a statement Thursday. "He chose to escalate the situation, brutally going on the attack. Today's sentence holds him accountable for his repeated attacks of an officer that day."

Webster's lawyers had argued that Webster's years of service, "exceptional character," "impeccable conduct" as a uniformed police officer and "love and devotion to his country" warranted a less severe sentence than the DOJ sought.

ABC News' Gabe Stern contributed to this report.