FBI Director James Comey took the unprecedented step of publicly pre-empting a Justice Department prosecution when he declared at a press conference Tuesday that “no reasonable prosecutor” would bring a case against Hillary Clinton for her use of a private email server.

The FBI’s job is to investigate crimes; it is Justice Department prosecutors who are supposed to decide whether or not to move forward. But in a case that had enormous political implications, Comey decided the FBI would act on its own.

“Although the Department of Justice makes final decisions on matters like this, we are expressing to Justice our view that no charges are appropriate in this case,” he said. Prosecutors could technically still file criminal charges, but it would require them to publicly disagree with their own investigators.

One of Comey’s likely motivations was avoiding the appearance that Department of Justice lawyers had biased the investigation due to their desire to avoid prosecuting a major party’s presidential nominee. He repeatedly assured the audience that “no outside influence of any kind was brought to bear.” Comey’s announcement also satisfied the public’s desire for a resolution sooner rather than later.

But Matthew Miller, who was a spokesperson for the Department of Justice under Attorney General Eric Holder, called Comey’s press conference “absolutely unprecedented, appalling, and a flagrant violation of Justice Department regulations.” He told The Intercept: “The thing that’s so damaging about this is that the Department of Justice is supposed to reach conclusions and put them in court filings. There’s a certain amount of due process there.”

Legal experts could not recall another time that the FBI had made its recommendation so publicly.

“It’s not unusual for the FBI to take a strong position on whether charges should be brought in a case,” said University of Texas law professor Steve Vladeck. “The unusual part is publicizing it.”

Given the extraordinary circumstances, Vladeck called it “both unusual and completely unsurprising that Comey went out of his way to make this statement.”

He added, “It’s certainly pre-emptive on Comey’s part.”

Attorney General Loretta Lynch was widely criticized for meeting with former President Bill Clinton last week while his wife was still under investigation. Lynch insisted that the conversation was perfunctory. She said on Friday that she would accept whatever recommendations career prosecutors and the FBI director made when they presented them to her.