A trial starting this week in Washington, D.C., is the biggest test yet in the Justice Department's efforts to hold accountable those responsible for the attack on the Capitol on Jan. 6, 2021, a violent assault that challenged the foundations of American democracy.
On trial is extremist leader Stewart Rhodes, founder of the Oath Keepers extremist group, and four associates.
Prosecutors and defence attorneys will make their opening statements on Monday and the trial will last several weeks.
Here is a look at what's to come:
WHO ARE THE OATH KEEPERS?
The anti-government group was founded in 2009 by Rhodes who was educated at Yale Law School and served briefly as a U.S. Army paratrooper before a training accident left him with a back injury.
The group was named after its stated goal of getting past and present members of the military, first responders and police officers to honour the promise they made to defend the Constitution against enemies.
They issued a list of orders that its members wouldn't obey, such as disarming citizens, carrying out warrantless searches and detaining Americans as enemy combatants in violation of their right to jury trials.
That relatively benign framing and leveraging of social media helped the group grow to one of the largest anti-government militia groups in U.S. History, but the internal dialogue was often darker, experts said.
Oath Keepers participated in the standoff with federal off with officials at Nevada's Bundy Ranch in 2014, and later along rooftops in Ferguson, Missouri after a grand jury declined to charge a police officer in the fatal shooting of 18-year-old Michael Brown.
The group would eventually embrace then-candidate Donald Trump's rhetoric and his false claims that the 2020 election was stolen.
WHY ARE THEY ON TRIAL?
On trial with Rhodes are Kelly Meggs, leader of the Florida chapter of the Oath Keepers; Kenneth Harrelson, another Florida Oath Keeper; Thomas Caldwell, a retired U.S. Navy intelligence officer from Virginia; and Jessica Watkins, who led an Ohio militia group.
They have been charged with seditious conspiracy in one of the most high profile cases to come out of the Jan. 6 riot at the U.S. Capitol.
Prosecutors say they spent several weeks amassing weapons, organising paramilitary training and readying armed teams outside Washington to stop Joe Biden from becoming president.