Former president Donald Trump plans to fly to New York on Monday and stay overnight before appearing in a specially secured Manhattan courthouse to be arraigned on still-unspecified criminal charges, people briefed on the arrangements said.

The first-ever indictment of a former president — who is also a 2024 White House hopeful — brings unusual security challenges to the courthouse complex in Lower Manhattan, even as it continues to roil the political landscape.

On Friday, Trump lashed out on social media at the judge assigned to the case and a prosecutor from the office of Manhattan District Attorney Alvin Bragg. Republican lawmakers focused their ire on Bragg, an elected Democrat, while Bragg’s deputy pushed back against demands from GOP committee chairs that the district attorney come to Capitol Hill and explain his investigation.

Being charged with, or convicted of, a crime would not disqualify Trump from running for president or holding the office. But the optics and logistics of campaigning while navigating a legal case could get complicated. For the moment, Trump and his advisers are ramping up their fundraising efforts and making the rounds of GOP lawmakers and party leaders, leaving his lawyers to negotiate his surrender to law enforcement and his security detail to coordinate logistics with police.

An advance team of Secret Service agents — mostly composed of New York field office agents — conducted a site tour of the courthouse on Friday to map Trump’s path in and out of the building, according to a law enforcement official involved in the planning.

The official, who spoke on the condition of anonymity to discuss the arrangements, said that “dozens and dozens of agents” will be required to secure the former president’s travel between Mar-a- Lago, his Florida home and private club, and New York.

The indictment announced Thursday evening remains under seal, which means the charges have not been made public. But a Manhattan grand jury has been hearing evidence about a payment made before the 2016 presidential election to Stormy Daniels, an adult-film actress, to keep her from publicly discussing an affair she says she had with Trump years earlier.

Bragg and his investigators have spent months probing whether Trump falsified business records connected to the Daniels payment in a way that could constitute a campaign-finance violation.

The New York probe is one of multiple criminal investigations that have engulfed Trump’s post-presidency. He is also the focus of investigations in Georgia and D.C. related to his efforts to overturn Joe Biden’s 2020 election victory and his handling of classified material at Mar-a-Lago.

Trump denies any wrongdoing and continues to accuse law enforcement agencies that investigate him of conducting political witch hunts. In a statement Thursday evening, he charged that Democrats “have lied, cheated and stolen in their obsession with trying to ‘Get Trump,’ but now they’ve done the unthinkable - indicting a completely innocent person in an act of blatant Election Interference. Never before in our Nation’s history has this been done.”

The next step in the criminal proceeding is Trump’s arraignment, which multiple people involved with the plans have said will happen on Tuesday afternoon. The former president will be fingerprinted, photographed and brought to the courtroom of Supreme Court Justice Juan Merchan upon surrendering before the proceeding, where he is expected to enter a not-guilty plea. If the charges have not already been made public, they will be unsealed by the time of the arraignment.

On Friday, Secret Service Director Kimberly Cheatle briefed her deputies about plans for Tuesday, the law enforcement official said, telling them that the agency will take “the necessary steps” to protect Trump from harm, including placing agents and officers in a bubble formation to separate him from approaching members of the public. But she also stressed that the Secret Service has not sought any special accommodations in the court’s standard processing and arraignment procedure, the official said, such as closing off courthouse hallways to the public.

In securing Trump’s safety, Secret Service agents will be primarily responsible for his entry to and exit from the courthouse, the official said. Court security officers will manage the former president’s movements inside the building, in the company of Trump’s security detail, and New York police officers will secure the outside streets surrounding the courthouse and along Trump’s motorcade route through the city.

The New York Police Department will have a heavier-than-normal presence around the courthouse, and officers who normally wear street clothes or suits have been directed to come to work in uniform in case there’s a need to monitor demonstrations, another law enforcement official said, also speaking on the condition of anonymity to discuss security arrangements.

The streets around the courthouse will be blocked off to traffic and street parking will be suspended, an official said. Court security officers who had scheduled vacation days or time off have been asked to report for duty anyway.

In D.C., the Capitol Police and the Office of the Sergeant-at-Arms sent a warning to Senate staffers on Friday that they anticipate “demonstration activity across the country related to the indictment of former President Trump.”

“While law enforcement is not tracking any specific, credible threats against the Capitol or state offices, there is potential for demonstration activity,” the authorities said, according to a statement first reported by Punchbowl News.

They also told staffers to expect an increase in Capitol Police and law enforcement presence around the Capitol in the coming days. Both chambers of Congress are in recess for the next two weeks in observance of the spring religious holidays.

Jacobs reported from New York. The Washington Post’s Mariana Alfaro also contributed to this report.