Fulton County District Attorney Fani Willis on Monday said she would announce this summer whether former President Donald Trump and his allies would be charged with crimes related to alleged interference in Georgia’s 2020 election.

Willis revealed the timetable in a letter to local law enforcement in which she asked them to be ready for “heightened security and preparedness” because she predicted her announcement may provoke a significant public reaction.”

In the letters, Willis said she will announce possible criminal indictments between July 11 and Sept. 1, sending one of the strongest signals yet that she’s on the verge of trying to obtain an indictment against Trump and his supporters.

“Please accept this correspondence as notice to allow you sufficient time to prepare the Sheriff’s Office and coordinate with local, state and federal agencies to ensure that our law enforcement community is ready to protect the public,” Willis wrote to Fulton Sheriff Patrick Labat.

Similar letters were hand delivered to Darin Schierbaum, Atlanta’s chief of police, and Matthew Kallmyer, director of the Atlanta-Fulton County Emergency Management Agency.

“We have seen in recent years that some may go outside of public expressions of opinion that are protected by the First Amendment to engage in acts of violence that will endanger the safety of those we are sworn to protect,” Willis wrote. “As leaders, it is incumbent upon us to prepare.”

Trump has called for mass demonstrations in response to overreach from prosecutors — triggering concerns about violent unrest not unlike the Jan. 6, 2021, insurrection he promoted.

Several legal observers closely following the Fulton investigation, which Willis launched more than two years ago, said the letters suggest that Willis will seek charges against the former president.

“It obviously seems to imply the case against Trump will be presented to a grand jury,” former Gwinnett County District Attorney Danny Porter said. “I don’t think any of the other targets would raise that level of caution. I think that’s the obvious implication.”

Norm Eisen, a former ethics czar under President Barack Obama who co-authored a Brookings Institute report on the Fulton probe, agreed.

“While she does not have the former president’s name in her letter, the evidence and the applicable law in Georgia point to the substantial likelihood that Donald Trump and his principal co-conspirators will be included when she follows through on the plans she confirms in this letter,” Eisen said.

For inspiration, Fulton authorities can look to the preparations that took place in Manhattan ahead of Trump’s arraignment earlier this month in a separate criminal case involving hush money payments.

Authorities erected barricades and shut down streets surrounding the courthouse. The police issued a stand-ready order for roughly 35,000 officers in the region as well as city, state and federal law enforcement agencies. About an hour before Trump’s afternoon court appearance, a number of Manhattan courtrooms were closed, according to published reports. There was also a total shutdown of the route the former president took to the courthouse from Trump Tower and from the courthouse to board his plane at LaGuardia Airport.

The Fulton sheriff’s office referred any questions about Willis’s letter to the DA’s office. An APD spokesman said the department stands “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 spokeswoman for the Atlanta-Fulton County Emergency Management Agency did not immediately respond to a request for comment.

This isn’t the first time law enforcement in Atlanta has been ramped up in response to the Fulton DA’s Trump investigation.

Last May, as a Fulton judge selected members of the special grand jury, the Fulton Sheriff’s office blocked off vehicle traffic on the streets surrounding the courthouse and stationed deputies with guns on many street corners with semi-automatic rifles. Snipers patrolled nearby rooftops as helicopters circled overhead. Law enforcement also deployed a SWAT team to protect jurors as they returned to their cars at the end of the day.

Six months later, before jurors interviewed Michael Flynn, Trump’s former national security adviser, they assigned heavily armed officers to guard the courthouse steps and brought in a bomb-sniffing dog.

Willis herself travels with a security detail and has equipped some members of her team with bulletproof vests and keychains with panic buttons.

Porter, a Republican, said he was somewhat surprised that prosecutors are waiting until the July term of the grand jury to present a potential case to a grand jury.

“I thought she’d do it faster,” he said. “But there is probably a tremendous amount of documentary evidence in terms of emails and texts they are having to go through.”

Willis had previously told a Fulton judge that indictment decisions were “imminent” back in January.

Since then, Trump’s attorneys have filed a wide-ranging motion seeking to dismiss Willis from the case, as well as any evidence compiled by the special grand jury. And prosecutors recently acknowledged they were interviewing several of the “alternate” GOP electors who had previously been labeled investigation targets, suggesting they had cut immunity deals with them and were learning brand new information.

After news of the letters became public, Trump’s legal team said in a statement that the correspondence does “nothing more than set for a potential timetable” for charging decisions.

“On behalf of President Trump, we filed a substantive legal challenge for which the DA’s Office has yet to respond,” attorneys Drew Findling, Jennifer Little and Marissa Goldberg said. “We look forward to litigating that comprehensive motion which challenges the deeply flawed legal process and the ability of the conflicted DA’s Office to make any charging decisions at all.”