Miami. Former U.S. President Donald Trump said Thursday that he was indicted for mishandling classified documents at his Florida estate, a remarkable development that makes him the first former president in U.S. history to face criminal charges by the federal government that he once oversaw.

The indictment carries unmistakably grave legal consequences, including the possibility of prison if he's convicted.

But it also has enormous political implications, potentially upending a Republican presidential primary that Trump had been dominating and testing anew the willingness of GOP voters and party leaders to stick with a now twice-indicted candidate who could face still more charges. 

And it sets the stage for a sensational trial centered on claims that a man once entrusted to safeguard the nation's most closely guarded secrets willfully, and illegally, hoarded sensitive national security information.

The Justice Department did not immediately confirm the indictment publicly. But two people familiar with the situation who were not authorized to discuss it publicly said the indictment included seven criminal counts. One of those people said Trump's lawyers were contacted by prosecutors shortly before he announced on his Truth Social platform that he had been indicted.

Within 20 minutes of his announcement, Trump began fundraising off it for his 2024 presidential campaign. He declared his innocence in a video and repeated his familiar refrain that the investigation is a “witch hunt.” He said he planned to be in court Tuesday afternoon in Miami, where a grand jury had been meeting to hear evidence as recently as this week.

The case adds to deepening legal jeopardy for Trump, who has already been indicted in New York and faces additional investigations in Washington and Atlanta that also could lead to criminal charges. But among the various investigations he faces, legal experts — as well as Trump's own aides — had long seen the Mar-a-Lago probe as the most perilous threat and the one most ripe for prosecution. Campaign aides had been bracing for the fallout since Trump’s attorneys were notified that he was the target of the investigation, assuming it was not a matter of if charges would be brought, but when.

Appearing Thursday night on CNN, Trump attorney James Trusty said the indictment includes charges of willful retention of national defense information — a crime under the Espionage Act, which polices the handling of government secrets — obstruction, false statements and conspiracy.

The case is a milestone for a Justice Department that had investigated Trump for years — as president and private citizen — but had never before charged him with a crime. The most notable investigation was an earlier special counsel probe into ties between his 2016 campaign and Russia, but prosecutors in that probe cited Justice Department policy against indicting a sitting president. Once he left office, though, he lost that protection.

The inquiry took a major step forward last November when Attorney General Merrick Garland, a soft-spoken former federal judge who has long stated that no person should be regarded as above the law, appointed Jack Smith, a war crimes prosecutor with an aggressive, hard-charging reputation to lead both the documents probe as well as a separate investigation into efforts to subvert the 2020 election.

The indictment arises from a months-long investigation into whether Trump broke the law by holding onto hundreds of documents marked classified at his Palm Beach property, Mar-a-Lago, and whether he took steps to obstruct the government’s efforts to recover the records.

Prosecutors have said that Trump took roughly 300 classified documents to Mar-a-Lago after leaving the White House, including some 100 that were seized by the FBI last August in a search of the home that underscored the gravity of the Justice Department’s investigation. Trump has repeatedly insisted that he was entitled to keep the classified documents when he left the White House, and has also claimed without evidence that he had declassified them.

Court records unsealed last year showed federal investigators believed they had probable cause that multiple crimes had been committed, including the retention of national defense information, destruction of government records and obstruction.

Since then, the Justice Department has amassed additional evidence and secured grand jury testimony from people close to Trump, including his own lawyers. The statutes governing the handling of classified records and obstruction are felonies that could carry years in prison in the event of a conviction.

It remains unclear how much it will damage Trump's standing given that his first indictment generated millions of dollars in contributions from angry supporters and didn’t weaken him in the polls. But no matter what, the indictment -- and legal fight that follows -- will throw Trump back into the spotlight, sucking attention away from the other candidates who are trying to build momentum in the race.