Former President Donald Trump is expected to travel to New York on Monday, sources familiar with the matter told ABC News.

He is expected to appear in court on Tuesday at the earliest, the sources said, on what is expected to be around two dozen counts - including felonies.

The exact charges are unknown since the indictment will not be unsealed until Trump appears in court.

-ABC News’ Aaron Katersky, Katherine Faulders, John Santucci

As legal experts speculate on what charges lay inside the sealed indictment ahead of former President Donald Trump's expected surrender on Tuesday afternoon, many predict that prosecutors could try out a new legal theory to justify bringing the charges.

"This could be a novel legal theory," said Kate Shaw, a law professor at Cardozo and ABC News contributor, speculating on what charges the public could see against Trump while stressing it's unknown until the indictment is unsealed.

Read more here.

-ABC News' Libby Cathey

Former President Donald Trump has been charged with around two dozen counts, including felonies, sources familiar with the sealed indictment told ABC News.

The exact charges remain unknown since the indictment will not be unsealed until Trump appears in court on Tuesday.

The Manhattan district attorney’s office declined to comment.

The Senate sergeant at arms is warning of potential demonstration activity related to the indictment of former President Donald Trump.

"While law enforcement is not tracking any specific, credible threats against the Capitol or state offices, there is potential for demonstration activity," an email obtained by ABC News said.

Capitol Police "is working with law enforcement partners, so you may observe a greater law enforcement presence on Capitol Hill," the email said, adding that there could be "nationwide impacts to Senate state offices."

The Capitol Police declined to comment and the sergeant at arms didn't immediately respond to ABC News' request for comment.

-ABC News' Luke Barr

President Joe Biden repeatedly declined to comment on the indictment when leaving the White House Friday morning to head to Mississippi.

Asked by ABC News if he had any reaction, Biden said, "No," and shook his head.

Reporters tried to get the president to comment on the issue from several different angles, but Biden did not bite each time.

Biden was asked if he was worried the indictment would further divide the country, and he said, "I have no comment on that."

Asked if he was worried about protests, Biden replied, "No, I'm not going to talk about the Trump indictment."

Later asked what the indictment said about the rule of law in this country, Biden said, "I have no comment at all on Trump."

Biden learned about the indictment through the news at the same time as the rest of the country, according to the White House press secretary.

Vice President Kamala Harris also declined to comment during a press conference in Lusaka, Tanzania.

-ABC News' Molly Nagle