Former President Donald Trump and Fulton County District Attorney Fani Willis are seen here. At least 8 fake electors have been granted immunity in the Georgia Trump investigation. (Photo courtesies: AFP/Getty Images/AP) Credit: AFP / Getty Images/AP

(CNN) — Fulton County District Attorney Fani Willis plans to announce this summer whether she’ll bring charges against former President Donald Trump or his allies for their attempts to overturn Georgia’s 2020 presidential election results, according to a letter obtained by CNN.

Willis told local law enforcement officials in a letter that she plans to make an announcement on possible charges between July 11 and September 1.

The letter is another strong indication that Willis is seriously weighing bringing racketeering and conspiracy charges in connection with Trump’s actions in the Peach State around the 2020 election, as CNN has reported.

“I am providing this letter to bring to your attention the need for heightened security and preparedness in coming months due to this pending announcement,” Willis, a Democrat, wrote.

In the letter addressed to the Sheriff of Fulton County Patrick Labat, who is in charge of courthouse security, Willis said that “open-source intelligence” has previously indicated that decisions in this case could provoke “significant” public reaction that could result in “violence.”

“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 in the letter.

The Atlanta Journal-Constitution first reported the letter.

CNN’s Ryan Young spoke with a police chief in metropolitan Atlanta who confirmed they also received a letter on Monday, detailing Willis’ desire for them to be prepared to assist with security and law enforcement preps ahead of any potential charges.

Fulton County’s fourth term of court is scheduled to begin on July 11, so Willis would bring any possible charging recommendations to the regularly seated grand juries, who each serve two-month terms, during that time frame.

Willis kicked off her sprawling investigation in early 2021 shortly after she took office, and soon after the infamous January phone call became public in which Trump pressured Georgia Secretary of State Brad Raffensperger to “find” the votes necessary for Trump to win Georgia’s electoral votes.

Investigators have at least three recordings of Trump pressuring Georgia officials, including a phone call that he made to the Georgia House speaker to push for a special legislative session to overturn Democrat Joe Biden’s 2020 victory in the state.

There is also a recording of Trump’s call to a top investigator with the Georgia Secretary of State’s office in December 2020, while they were looking into quashed allegations of irregularities with signature-matching in Cobb County in the Atlanta metropolitan area.

The Fulton County probe expanded beyond the Trump phone calls to include false claims of election fraud to state lawmakers, the fake elector scheme, efforts by unauthorized individuals to access voting machines in one Georgia county and threats and harassment against election workers.

This story has been updated with additional details.