The prosecutor in Atlanta investigating whether then-President Donald Trump and his allies illegally meddled in the 2020 election in Georgia said Monday she expects to announce charging decisions in the case this summer and urged "heightened security."

Fulton County District Attorney Fani Willis wrote in a letter to county Sheriff Pat Labat that she expects to announce the decisions sometime between July 11 and Sept. 1. She said she wanted to give Labat time to coordinate with local, state and federal agencies "to ensure that our law enforcement community is ready to protect the public."

"Open-source intelligence has indicated the announcement of decisions in this case may provoke a significant public reaction," Willis wrote in the letter, adding that some could involve "acts of violence that will endanger the safety of our community."

As leaders, they need to be prepared, she wrote, adding that her team would be in touch to talk about arrangements.

The letter was first reported by The Atlanta Journal-Constitution, which reported that letters were also sent to Atlanta's police chief and the head of the Atlanta-Fulton County Emergency Management Agency.

The Atlanta Police Department confirmed receipt of a letter from Willis and said it would "continue to monitor the potential for unrest throughout our city."

"We stand ready to respond to demonstrations to ensure the safety of those in our communities and those exercising their First Amendment right, or to address illegal activity, should the need arise," a department statement said.

Willis has been investigating whether Trump and his allies broke any laws as they tried to overturn his narrow election loss to Democrat Joe Biden in Georgia.

She opened the investigation in early 2021, shortly after a recording of a phone call between Trump and Georgia Secretary of State Brad Raffensperger was made public. In that call, Trump suggested the state's top elections official could help "find" the votes needed to overturn his loss in the state.

It has become clear since then that the scope of her investigation has expanded far beyond that call.

Trump, who last fall announced a 2024 bid for the White House, already faces criminal charges in New York. A Manhattan grand jury in March indicted him on 34 counts of falsifying business records to cover up hush-money payments to a porn actor during the 2016 presidential election.

New York police had said ahead of his arraignment there that they were ready for large protests by the former president's supporters, who believe any charges against him are politically motivated. And while hundreds of onlookers, protesters, journalists and some politicians did show up, fears that unruly crowds would cause chaos ultimately proved unfounded.

Meanwhile in Washington, federal grand juries are investigating efforts by Trump and his allies to undo the results of the 2020 presidential election and the potential mishandling of classified documents by Trump at his Florida estate. Justice Department prosecutors have questioned numerous Trump administration officials before the grand jury. It's not clear when those probes, both overseen by a special counsel appointed last fall, might conclude or who if anyone might be charged.

Trump's legal team in Georgia — Drew Findling, Jennifer Little and Marissa Goldberg — said in a statement that Willis' announcement to law enforcement "does nothing more than set forth a potential timetable" for decisions Willis had already said were coming.

"On behalf of President Trump, we filed a substantive legal challenge for which the D.A.'s Office has yet to respond," the statement said. "We look forward to litigating that comprehensive motion which challenges the deeply flawed legal process and the ability of the conflicted D.A's Office to make any charging decisions at all."

Trump's legal team last month filed a motion seeking to toss out a report drafted by a special grand jury that was impaneled to aid Willis' investigation. They also asked the court to prohibit Willis from continuing to investigate or prosecute Trump. A judge gave Willis until May 1 to respond.