Former President Donald Trump is set to make history for all the wrong reasons – again. Trump’s appearance Tuesday afternoon (June 13) in a federal courtroom in Miami will mark the first time the Justice Department has ever charged a former president with a crime.

Federal prosecutors will arraign the 45th U.S. president on 37 felony counts connected with his alleged mishandling of classified documents after leaving the White House.

According to the federal indictment filed on Thursday (June 8), the ex-president “endeavored to obstruct the FBI and grand jury investigations and conceal retention of classified documents." It also names former White House valet and Trump aide Walt Nauta as a co-conspirator.

Prosecutors allege that Trump stored classified documents that contain sensitive military information for the United States and foreign countries at his Mar-a-Lago residence in Florida, which was not “an authorized location for the storage, possession, review, display, or discussion of classified documents" after he left office. The indictment also alleges that Trump showed classified documents to others.

Here are three things to know about this latest development:

Trump plans to plead not guilty, CBS News reports. His advisers said Monday (June 12) the former president is “defiant and confident” about the charges, which he plans to “fight.”

According to federal prosecutors, Trump’s multiple violations include allegedly concealing evidence and obstructing justice by hiding the documents with the intent of obstructing an FBI investigation, The Washington Post reports. He’s also accused of making false statements to investigators, claiming that he did not possess the classified files that the government sought, as well as suggesting that one of his attorneys lie to the federal investigators and help hide or destroy documents.

The government charged Trump with 31 counts of violating part of the Espionage Act, an anti-spy law enacted after World War I. According to Reuters, the law criminalizes a range of acts connected to mishandling government documents related to national defense. Trump and Nauta also tampered with grand jury evidence when they allegedly tried to withhold evidence from the jurors.

If convicted, Trump faces a long prison sentence. The maximum punishment is 10 years for each count of unlawful retention of national defense information, according to The Post. He could get up to 20 years each on the obstruction and grand jury tampering charges, as well as five years for each false statement charge.