ATLANTA (AP) — The prosecutor who's investigating whether Donald Trump and others broke the law by trying to pressure Georgia officials to overturn Joe Biden's presidential election victory is asking the FBI for security help after the former president railed against prosecutors investigating him.

Fulton County District Attorney Fani Willis on Sunday wrote a letter to the FBI office in Atlanta asking for a risk assessment of the county courthouse, where her office is located, and government center. She also asked the FBI to provide protective resources, “to include intelligence and federal agents.”

At his rally Saturday night outside Houston, Trump lashed out against the ongoing investigations in New York, Georgia and Washington and called on his supporters to stage mass protests if he is mistreated by them. In her letter, Willis quoted comments Trump made at the rally.

“If these radical, vicious, racist prosecutors do anything wrong or illegal, I hope we are going to have in this country the biggest protest we have ever had in Washington, D.C, in New York, in Atlanta and elsewhere, because our country and our elections are corrupt,” Trump said.

The comments were particularly notable given Trump’s role in inciting the Jan. 6, 2021, storming of the Capitol building. Trump also suggested he might pardon those charged for their role in the riot if he runs for president again and wins reelection.

Willis last year opened an investigation into any potential attempts to improperly influence the 2020 general election in Georgia by Trump and his associates. A special grand jury is set to be seated May 2 to aid in that investigation and Willis asked the FBI to take the steps she requested well in advance of that date.

“My staff and I will not be influenced or intimidated by anyone as this investigation moves forward,” Willis wrote.

She added that her office has already taken steps to address security concerns “considering the communications we have received from persons unhappy with our commitment to fulfill our duties.” She said she's also working with county officials on the need for extra security measures as the investigation progresses.

But she said security concerns were “escalated” over the weekend as Trump focused on the prosecutors looking into his actions, calling them “vicious, horrible people” and “racists.” The rhetoric is especially alarming, Willis wrote, in light of Trump's suggestion that if he returns to the White House, he could give pardons to people who stormed the U.S. Capitol last year in an effort to block the certification of Biden’s win.

“We must work together to keep the public safe and ensure that we do not have a tragedy in Atlanta similar to what happened at the United States Capitol on January 6, 2021,” Willis wrote in the letter to the FBI.

Jenna Sellitto, a spokesperson for the FBI in Atlanta, confirmed receipt of the letter but declined to comment further.

In his pushback against the various investigations centered on him, Trump has taken particular aim at New York Attorney General Letitia James, who recently said her office has uncovered evidence that Trump’s company used “fraudulent or misleading” valuations of his properties to secure loans and tax benefits. That includes playing a video at a previous rally that features footage of her vowing to take on Trump as she ran for election.

Trump did not mention James, Willis, or any of the others by name Saturday.

Willis has declined to speak about the specifics of her investigation, but in a recent interview with The Associated Press, she confirmed that its scope includes — but is not limited to — a Jan. 2, 2021, phone call between Trump and Georgia Secretary of State Brad Raffensperger, a November 2020 phone call between U.S. Sen. Lindsey Graham and Raffensperger, the abrupt resignation of the U.S. attorney in Atlanta on Jan. 4, 2021, and comments made during December 2020 Georgia legislative committee hearings on the election.

In a statement earlier this month, Trump said his call to Raffensperger was “perfect” and said he did not say anything wrong. Graham has also denied any wrongdoing.