Donald Trump is facing 31 counts of unlawfully retaining classified documents.
Donald Trump will surrender Tuesday to face federal charges of mishandling US government secrets -- the latest and most serious in a string of probes threatening his bid to win back the White House.
Security was tight around the federal courthouse in downtown Miami where Trump is to enter a plea in the first federal criminal case filed against a former US president.
A judicial source said Trump will be processed like other defendants. He will have his fingerprints taken digitally and a photo of him will be uploaded into the court records but not released to the public.
Dozens of Trump supporters had gathered near the courthouse as the 3:00 pm (1900 GMT) court appearance approached including some wearing "Make America Great Again" baseball caps and one with a sign reading "Indict Jack Smith," the special counsel who brought the charges against Trump.
Police, including some on horseback and bicycles, were out in force braced for protests and the possibility of unrest, but the atmosphere was festive with a local radio station blasting Cuban salsa music.
Trump, who is to make a 25-minute motorcade journey from his Doral golf course to the courthouse, took to his Truth Social platform Tuesday morning to attack Smith, calling the prosecutor a "thug" and a "lunatic."
Trump is facing 31 counts of unlawfully retaining classified documents, punishable by up to 10 years in prison, conspiracy to obstruct justice, making false statements and other offenses.
The rebellious Republican said he would plead not guilty but would not make any statement from the courthouse after the hearing.
"I'll just say not guilty," Trump told conservative radio host Howie Carr late Monday.
"I did nothing wrong. Presidential Records Act, it's not even a criminal event. There is no criminality here. It's ridiculous."
- 'Dumbfounded' -
The pugnacious billionaire, who turns 77 on Wednesday, is accused of willfully hoarding dozens of classified documents he took unlawfully to his beachfront mansion in Florida upon leaving office in 2021, refusing to return them and conspiring to obstruct investigators seeking their recovery.
He is also accused of sharing sensitive US secrets with people who had no security clearance.
Lazaro Ezenar, 48, was among those who turned out to back the former president.
"I'm here for the simple fact of the unlawful indictment of Donald J. Trump. I can't believe he's going through this again," Ezenar told AFP, referring to the criminal charges brought against Trump in a hush-money case in New York -- a first for a former US president.
"This is historic and I'm just dumbfounded that, as a country that is a beacon to the world, I have to see this show that is disgracing what America represents."
The runaway frontrunner in the 2024 Republican primary has vowed to stay in the race regardless of the outcome of the documents case.
The 49-page indictment, dismissed by Trump as "ridiculous," includes photographs showing boxes of documents stacked at Mar-a-Lago, his Palm Beach residence, in a ballroom and in a bathroom and shower.
- 'Eye for an eye' -
Trump is expected to fly to his golf club in Bedminster, New Jersey, after Tuesday's hearing to restate his innocence in a speech before supporters.
His legal woes are only just beginning, as he faces multiple felony counts in the New York fraud case involving porn star Stormy Daniels, set for trial next March.
Smith, the special counsel, is also looking into Trump's involvement in the 2021 US Capitol riot, and state and federal investigators are scrutinizing his efforts to subvert the 2020 election he lost to Democrat Joe Biden.
Trump's allies in Congress and rivals for the presidential nomination have largely circled the wagons following his latest indictment, decrying the alleged "weaponization" of the government against conservatives.
Some Republican lawmakers have been criticized for rhetoric that could inspire violence, including Arizona's Andy Biggs, who tweeted: "We have now reached a war phase. An eye for an eye."
The Southern District of Florida is known as a "rocket docket" court, legal slang for locations that push for swift justice, and authorities have not ruled out completing a trial before the 2024 election.
Much of the focus in the preliminary proceedings will be on District Court Judge Aileen Cannon, a Trump appointee who was allocated the case at random and will have enormous sway over how fast things move.
Another judge will oversee Tuesday's hearing.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)