The bombshell revelations Tuesday by former White House aide Cassidy Hutchinson could be key to bringing a possible criminal case against former president Donald Trump, legal experts said.

Hutchinson delivered shocking testimony that Trump knew his supporters were armed before they assaulted the US Capitol on Jan. 6, 2021 - and wanted to go with them.

“It’s clear to me that yesterday’s compelling testimony under oath – that Trump knew his supporters were armed when he exhorted them to go to the Capitol, made clear that he wanted the magnetometers [the metal detectors at Trump’s Ellipse rally] disarmed so those with heavy armor and AR-15s could storm the Capitol along with him leading the charge, and actually said he didn’t fear the mob he had assembled because they weren’t going to hurt HIM – combined to make an overwhelming case for indicting the former president,” Laurence Tribe, an emeritus professor at Harvard Law School, said in an e-mail.

Renato Mariotti, a legal analyst and former federal prosecutor in Illinois, said on Twitter and in a column in Politico, that Hutchinson’s testimony is a “game changer” that “actually moved the ball forward significantly towards a potential [Department of Justice] prosecution of Trump.”

“Testimony that Trump said he didn’t ‘f-ing care that they have weapons. They’re not here to hurt me’ and that they would be going to the Capitol later is precisely the sort of ‘smoking gun’ evidence needed to prove that the person speaking meant to incite imminent violence,” Mariotti said in a tweet.

8/ Testimony that Trump said he didn’t “f-ing care that they have weapons. They’re not here to hurt me” and that they would be going to the Capitol later is precisely the sort of “smoking gun” evidence needed to prove that the person speaking meant to incite imminent violence.

Alan Rozenshtein, a former Justice Department official who teaches at the University of Minnesota Law School, told The New York Times, “There’s still a lot of uncertainty about the question of criminal intent when it comes to a president, but what just happened changed my bottom line.”

“I have gone from Trump is less than likely to be charged to he is more than likely to be charged,” he said.

Sol Wisenberg, a former deputy to Ken Starr, told the Times’s Peter Baker, “This is the smoking gun.”

“There isn’t any question this establishes a prima facie case for his criminal culpability on seditious conspiracy charges,” he said.

Did Trump commit a crime? "This is the smoking gun," Sol Wisenberg, a former deputy to Ken Starr, tells me about today's hearing. "There isn’t any question this establishes a prima facie case for his criminal culpability on seditious conspiracy charges."

David Laufman, a former senior Justice Department lawyer now in private practice, told The Washington Post that Hutchinson’s testimony “contained credible nuggets of information that would support” prosecutors viewing Trump as an investigative target in a seditious conspiracy investigation.

“This witness provided credible testimony under oath, attributing foreknowledge of the impending violence to the president,” said Laufman, who represents some of the U.S. Capitol Police officers injured in the Jan. 6 attack. “Whether at the end of the day the department can conclude it can prove beyond a reasonable doubt that Trump joined a conspiracy remains to be seen, because there may well be an extraordinarily high bar for prosecutors and department leadership to satisfy that standard.”

US Representative Liz Cheney, vice chairman of the Jan. 6 committee, which called Hutchinson to testify, retweeted an article by conservative writer and attorney David French that said, “Hutchinson’s sworn testimony closes a gap in the criminal case against Trump, and Trump is closer to a credible prosecution than ever before.”

The Case for Prosecuting Donald Trump Just Got Much Stronger https://t.co/qFm2fiJZsM

“Trump was not a man trying to stop a riot. The evidence continues to grow that he was instead stoking violence and inflaming the mob, all while doing the bare minimum to establish some degree of plausible deniability,” French wrote.

Neal Katyal, a Georgetown University law professor and former acting solicitor general of the United States, told NPR Tuesday that Hutchinson’s testimony “that Trump knew these people had guns - he said, don’t worry, take the metal detectors away; those people aren’t here to hurt me - and all the other stuff she detailed today, it’s incredibly damning. It makes the federal case not just against Donald Trump but Mark Meadows and others very, very strong.”

Katyal tweeted Tuesday, “This witness has directly implicated Donald Trump in the violence on January 6. ‘Take the magnometers away’ ‘They aren’t here to hurt me.’ This is devastating.”

Jed Shugerman, a Fordham University law professor, tweeted that he’d previously been vocal about thinking that the case against Trump was weak but that he changed his mind when he heard Hutchinson’s testimony about Trump and a “heavily armed mob.”

He said Trump asking for the metal detectors to be taken away “was a *material* step or attempt that obviously would make the mob more dangerous to everyone.” He also said he previously argued that Trump’s speech “was impossible to distinguish from regular political speech, but now I think the material step/attempt to keep the crowd heavily armed makes the case easily distinguishable.”

Legal experts have suggested that Trump could be charged with a variety of federal crimes, including seditious conspiracy, conspiracy to defraud the United States, obstructing an official proceeding, and inciting an insurrection. (Trump’s efforts to overturn the election in Georgia are also being investigated by a state grand jury there.)

Constitutional scholar Frank Bowman, a professor at the University of Missouri School of Law, said that after Hutchinson’s testimony, “The particular crime I suppose we now get closer to is seditious conspiracy,” which carries a maximum sentence of 20 years.

A seditious conspiracy charge can be brought when two or more people agree to employ force to “prevent, hinder, or delay the execution of any law of the United States.” Some members of the Oath Keepers and Proud Boys are already facing the charge in connection with the Capitol riot.

He said Trump was plainly trying to “prevent, hinder, or delay” the Electoral College count, but the question of whether force was part of the plan is the “tricky bit” in the case.

“The question for Trump is: Was this component of force part of this conspiratorial agreement or plan? This testimony from yesterday gets you closer to that,” he said. “It still remains difficult to prove.”

In the end, the choice of whether to file federal criminal charges will be up to US Attorney General Merrick Garland. For months, Garland has kept mum on whether prosecutors are looking at Trump’s conduct. But in recent days, federal agents have served search warrants and subpoenas, and conducted interviews that show the probe is moving closer to Trump’s inner circle, the Post reported.

“This is all about what Merrick Garland is going to decide,” said Bowman. “He’s the guy who’s going to have to pull the trigger, if it’s pulled.”

“Does the testimony that [Hutchinson] provided improve a possible case against Trump? You bet it does. Is it determinative? No. Does it change the calculus of Merrick Garland? I have not a clue,” he said.

Jeremiah Manion of the Globe staff contributed to this report. Material from Globe wire services was used in this report.

Martin Finucane can be reached at martin.finucane@globe.com.

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