Pro–Donald Trump rioters could face serious penalties for subverting the presidential election process.

More than 60 people were arrested on Wednesday after rioters breached the Capitol, assaulted officers, and stole items, including government laptop, law enforcement said on Thursday. Additionally, the stolen laptop may have contained “sensitive national security information,” CBS News reported.

Michael Sherwin, U.S. attorney for the District of Columbia, told reporters on Thursday that prosecutors filed 55 cases, 15 of which involve federal crimes, related to the riots—with more to come. The charges range from unlawful entry to possessing firearms and Molotov cocktails.  

One adult male repeatedly punched an officer in the chest inside the Capitol, according to charges filed on Thursday. Another was accused of carrying a pistol.

The Justice Department has also opened a “federal murder case” involving the death of a police officer, NPR reported Thursday evening.

Several others were arraigned on Thursday at the Superior Court of the District of Columbia for unlawful entry into the Capitol and violating curfew, relatively minor charges. They were released from custody and ordered to stay out of Washington, D.C., unless they were also involved in the criminal cases.

For the more serious cases, seditious conspiracy, rioting, and insurrection charges “are on the table,” Sherwin said.   

Rioters with felony charges like unlawfully and violently entering the House floor could face five years of prison, said Stanford University law professor David Sklansky. Meanwhile, assaulting a federal officer with a weapon could mean 20 years of incarceration, particularly if the officer was injured, he added.

Following the nationwide protests over the killing of George Floyd last year, President Trump signed an executive order that called for up to 10 years’ imprisonment for vandalism or destruction of “historical monuments, statues, and memorials.” But because the Capitol siege seemed to be intended to interfere with Electoral College vote counting, the prison sentence could rise to 20 years, Sklansky explained.

“Breaking into the nation’s Capitol to disrupt the business of Congress on a particularly critical day of American democracy is a pretty serious violation,” Sklansky said. “It’s hard to see the vandalizing of a monument as worse than breaking into the Capitol, disrupting members of Congress, and preventing the government from formalizing the results of a presidential election.”

Dan Farber, a law professor at the University of California at Berkeley, pointed out that seditious conspiracy charges are applicable when two or more people use “force to prevent the execution of any law in the United States.”

“Clearly they were trying to do that,” said Farber, referring to efforts to stop the electoral voting count.

Among the challenges in charging rioters with seditious conspiracy, however, is the difficulty in determining whether their decision to breach the Capitol was planned or spur of the moment, he said. In such cases, prosecutors would need to know “more about how this was organized.”

“This didn’t look like a military assault, but it also didn’t look spontaneous,” he explained.

Ultimately it will be up to prosecutors to determine, based on evidence, how tough an approach to take. In Farber’s view, the riot was severe considering that it was “specifically designed to not just throw paint on stuff or on a building, but something designed to prevent a crucial government action and that was done with force.” 

But John Dermody, a counsel at the O’Melveny law firm, said it’s unlikely that federal prosecutors will charge rioters with seditious conspiracy because Washington, D.C. prosecutors generally want to avoid politicizing their cases. While seditious conspiracy charges “do bring potentially much higher penalties,” he said, the penalty for assaulting a federal officer is already severe. Prosecutors can levy the rioters with more conventional charges that could act as a deterrent for others to commit similar crimes, without having to deal with the politics that would come from charging them with seditious conspiracy.

“Make no mistake, the riots were extraordinary, and the attack on the Capitol was shocking and not business as usual in D.C. by any measure,” said Dermody, who previously worked at the National Security Council and the Department of Homeland Security. That said, D.C. prosecutors are used to dealing with “crimes related to protests” and generally try to avoid bringing politics into their line of work, he said.

“I think there’s a reason why with the Sedition Act, there’s not a long history of it being used,” Dermody said. 

As for President Trump being charged with inciting the riots, Sklansky said that would be unlikely. Despite his speech just before, in which he exhorted his supporters to “fight,” Sklansky said it would be difficult to prove that his intent was to have people illegally enter the Capitol by force or violence. 

“The way in which Donald Trump threw matches into the spilled gasoline, into the conspiracy theories of this election is an impeachable offense, but nonetheless, it would be difficult to charge him with criminal acts,” Sklansky said.

And even if Trump were charged with a crime, would he be able to pardon himself? 

“Who knows?” said Farber. “The one thing you got to say about Trump is that you just don’t know.”

Story updated on Jan. 7 at 8:15 PM ET to include the reported opening of a federal murder case involving the death of an officer.

More politics coverage from Fortune:

• “We will never concede”: How Donald Trump incited an attack on America
• Democrats plan to use Senate win to pass $2,000 stimulus checks
• Photos: A look at the nationwide riots on Wednesday
• Attempted coup at Capitol presents key opportunity for cyberattack, experts warn
• Betting odds heavily favored Georgia’s GOP candidates, then suddenly collapsed. What went wrong?