As federal law enforcement officers sift through evidence tied to the attack on the U.S. Capitol, they have tried to determine what compelled rioters to force their way into the building. Namely, did any of them plan to kill or capture lawmakers or their staffers? 

Officials said they nay have found clues to that question from one of the mob's most distinctive figures: Jacob Anthony Chansley, the shirtless, tattooed man often referred to as "QAnon Shaman," who stood out in a headdress made of coyote skin and buffalo horns.

In a court filing late Thursday, federal prosecutors in Phoenix wrote that "strong evidence, including Chansley's own words and actions at the Capitol, supports that the intent of the Capitol rioters was to capture and assassinate elected officials in the United States government."

On Friday, however, Assistant U.S. Attorney Todd Allison walked back the claim of an assassination plot, saying that while it "may very well be appropriate at a trial," raising it at this stage could "mislead the court."

The 18-page memo, which asked a judge to keep Chansley detained before his trial, said the 33-year-old Arizona man left an ominous note for Vice President Mike Pence at his desk in the Senate chamber: "It's only a matter of time, justice is coming."

Chansley - who goes by Jake Angeli - was arrested and charged last week in connection to his role in the riot.

Defense attorney Gerald Williams said in court Friday that his client "was there merely acting as a protester," and that there was no evidence he engaged in violence.

But Magistrate Judge Deborah Fine ordered him held until trial, citing evidence that he incited the mob inside the Capitol and ignored pleas from police to desist.

"This is not a protest. This is a riot, this is an insurrection," she said. "Mr. Chansley's idea of protesting is committing the unlawful acts that we're discussing here," which she described as "frightening not only to people at the Capitol but people across the United States of America."

Acting D.C. U.S. Attorney Michael Sherwin downplayed the idea of a specific conspiracy or plan to kidnap or kill lawmakers.

"We don't have any direct evidence of kill capture teams," Sherwin said at a Friday news briefing.

In an earlier a statement to The Washington Post, St. Louis attorney Albert Watkins said he had been retained as Chansley's lawyer and called for President Donald Trump to pardon him.

Watkins claimed that Chansley acted in a "peaceful and compliant fashion" toward law enforcement and was cooperating with their investigation. Besides, he argued, the Arizona man only went to the Capitol because he was following Trump's invitation.

"He took seriously the countless messages of President Trump. He believed in President Trump," Watkins said. "Like tens of millions of other Americans, Chansley felt - for the first time in his life - as though his voice was being heard."

Law enforcement officials have cautioned that there may be a variety of motives among those who stormed the Capitol. An FBI investigation is seeking to determine whether some intended to do more than disrupt the certification of President-elect Joe Biden's victory, The Post reported last week.

One man, for instance, was arrested and accused of carrying a pistol on the Capitol grounds. Others wore tactical gear or brought zip ties, which can be used as handcuffs, officials said. And another was arrested after his truck was spotted nearby, allegedly with 11 molotov cocktails inside.

Chansley, who called the FBI himself to acknowledge that he was in the riot, told investigators that "he came as a part of a group effort, with other 'patriots' from Arizona, at the request of the President that all 'patriots' come to D.C. on January 6, 2021."

A fixture at far-right events in Arizona for the past two years, he has often professed his support for Trump and QAnon, the baseless online conspiracy theory. His body is heavily tattooed with insignia adopted by white nationalists.

Speaking to The Post last week, he said he was not afraid of arrest.

"I trust in God and I know that I didn't do anything wrong," he said. "And even if I was arrested, wasn't Gandhi arrested a lot? Wasn't Martin Luther King Jr. arrested a lot? Wasn't Jesus arrested? I put my trust in God, not the government."

Since his arrest last week, Chansley again made headlines after his mother, Martha Chansley, said he had been starving himself in jail because he "gets very sick if he doesn't eat organic food." The local office for the U.S. Marshals Service told KNXV that it would comply with a judge's order to provide all-organic meals in line with his shaman diet.

Watkins has successfully sought pardons for other high-profile clients, including Mark and Patricia McCloskey, the St. Louis couple who waved guns at protesters marching by their house last summer. Missouri Republican Gov. Mike Parson has twice said he will pardon the two if they are convicted on gun charges.

While it is unclear if Chansley can be tried and convicted before Trump leaves office on Jan. 20, it could still be possible for the president to pardon him beforehand - though, as the Department of Justice points out, such a move would be "highly unusual."

Trump has pardoned both Michael Flynn, his former national security adviser, and Joe Arpaio, the former Maricopa County sheriff, before they were sentenced.

In recent weeks, the lame-duck president has issued a rapid flurry of pardons to allies, friends and fellow Republicans, including full pardons to some who pleaded guilty to lying to federal law enforcement during the Russia investigation.

Watkins also called on Trump to pardon "other like-minded, peaceful individuals who accepted the president's invitation with honorable intentions."

While prosecutors have pointed out that Chansley brought a spear with him inside the Capitol, Watkins noted that his client also brought a megaphone, "so his voice could be heard."

"My client had heard the oft-repeated words of President Trump," Watkins said. "The words and invitation of a president are supposed to mean something."