A leader of the Proud Boys who led the far-right organization's infamous march to the US Capitol on January 6, 2021, has been sentenced to 17 years in prison -- among the longest sentences handed down yet for a convicted rioter.

Joe Biggs was convicted by a Washington, DC jury of several charges including seditious conspiracy for attempting to forcibly prevent the peaceful transfer of power from then-President Donald Trump to Joe Biden after the 2020 election.

"Our Constitution and laws give you so many important rights that Americans have fought and died for and that you yourself put on a uniform to defend," District Judge Timothy Kelly said in handing down the sentence. "People around the world would give anything for these rights."

But January 6, 2021, Kelly said, "broke our tradition of the peaceful transferring of power" in the United States.

"The nature of the constitutional moment we were in that day is something that is so sensitive that it deserves a significant sentence," he said.

Prosecutors initially asked Kelly to sentence Biggs to 33 years in prison -- nearly double the longest sentence a defendant has received related to the January 6, 2021 attack -- arguing that Biggs and his codefendants "intentionally positioned themselves at the vanguard of political violence in this country" for years and on January 6, 2021 sought to "change the course of American history."

But Kelly went significantly below that request, saying that he did not want to "minimize the violence that did occur" during the Capitol attack, but that he had to be conscious of what other people have been sentenced to for conduct related to January 6, 2021 as to not create large or unwarranted disparities.

The hefty sentence is the second longest sentence handed down for a defendant convicted as part of the Capitol attack. Oath Keeper leader and founder Stewart Rhodes has received the longest sentence of 18 years in prison.

'My curiosity got the best of me'

In a passionate appeal to the judge, Biggs, clad in an orange prison jumpsuit, said that "I know that I have to be punished and I understand," but added "please give me the chance, I beg you, to take my daughter to school and pick her up."

"I know that I messed up that day, but I am not a terrorist," he said through tears. Biggs said that he was "seduced" by the mob and "just moved forward.

"I wanted to see what would happen," he said. "My curiosity got the best of me and I'm going to have to live with that for the rest of my life."

During a monthslong, and at times tumultuous trial, prosecutors presented evidence that Biggs and three of his codefendants -- Ethan Nordean, Zachary Rehl and Enrique Tarrio -- plotted and broadly encouraged violence in the lead up to the Capitol attack.

When the riot broke out, Biggs, Nordean, and Rehl stood back while others -- including the fifth defendant Dominic Pezzola -- attacked police on the front line and pushed into the Capitol, prosecutors argued at trial.

Four of the defendants, Biggs, Tarrio, Nordean and Rehl, were convicted of seditious conspiracy, while Pezzola was acquitted of that charge.

All five Proud Boys were found guilty of other charges related to January 6, including: obstruction of an official proceeding, conspiracy to prevent an officer from discharging any duties, obstruction of law enforcement during civil disorder, destruction of government property and aiding and abetting.

In a court filing before the sentencing hearing Thursday, prosecutors wrote that "the conduct of these defendants is more egregious than that of the Oath Keeper defendants and warrants greater sentences."

Biggs, Kelly ruled earlier in the hearing Thursday, was subject to harsher sentencing penalties for domestic terrorism because he ripped down a fence on Capitol grounds during the riot that separated law enforcement officers from the mob, taking the mob one step closer to breaching the Capitol.

The Justice Department has previously sought the same enhancement in other January 6-related cases, though judges have rarely applied it -- notably doing so for members or associates of the far-right Oath Keepers.

The mob's breach on the Capitol "brought the legislative branch to heel" prosecutor Jason McCullough said in arguing for the enhancement, and "pushed us to the edge of a constitutional crisis."

McCullough continued, "When a parent considers whether they can take a child to a polling place and they think twice about that, when a couple decides if they should attend an inauguration and they think twice about that -- that's what [the Proud Boys] aimed to do — they aimed to intimidate and terrify elected officials, law enforcement, and the rest of the country that they didn't agree with, and make them heel to their point of view."

This story has been updated with additional developments.