ALEXANDRIA, Va. (AP) — Former FBI Director James Comey appeared in court on Wednesday, kick-starting a criminal case against him that legal experts say presents significant hurdles for the prosecution and will likely be a challenge for the Justice Department to win.

Comey was indicted in North Carolina on Tuesday on charges of making threats against President Donald Trump related to a photograph he posted on social media last year of seashells arranged in the numbers "86 47." The Justice Department contends those numbers amounted to a threat against Trump, the 47th president. Comey has said he assumed the numbers reflected a political message, not a call to violence against the Republican president, and removed the post as soon as he saw some people were interpreting it that way.

WATCH: James Comey indicted over social media post Trump's DOJ says crossed a line

The indictment is the second against Comey, a longtime adversary of Trump dating back to his time as FBI director, over the past year. The first one, on unrelated false-statement and obstruction charges, was tossed out by a judge last year. Now prosecutors pursuing the threats case face their own challenge of proving that Comey intended to communicate a true threat or at least recklessly discounted the possibility that the statement could be understood as a threat.

The indictment accuses Comey of acting "knowingly and willfully," but its sparse language offers no support for that assertion. Acting Attorney General Todd Blanche declined to elaborate at a news conference on what evidence of intent the government has. But broad First Amendment protections for free speech, Supreme Court precedent and Comey's public statements indicating that he did not intend to convey a threat will likely impose a tall burden for the government.

"Here, '86' is ambiguous — it doesn't necessarily threaten violence and the fact that it was the FBI Director posting this openly and notoriously on a public social media site suggests that he didn't intend to convey a threat of violence," John Keller, a former senior Justice Department official who led a task force to prosecute violent threats against election workers, wrote in a text message.

The case was charged in the Eastern District of North Carolina, the location of the beach where Comey has said he found the shells. He is set to make his first court appearance Wednesday at the federal courthouse in Alexandria, Virginia, the state where he lives.

What the law says on threats

The Supreme Court has held that statements are not protected by the First Amendment if they meet the legal threshold of a "true threat."

That requires prosecutors to prove, at a minimum, that a defendant recklessly disregarded the risk that a statement could be perceived as threatening violence. In a 2023 Supreme Court case, the majority held that prosecutors have to show that the "defendant had some subjective understanding of the threatening nature of his statements."

Meanwhile, the Supreme Court has found that hyperbolic political speech is protected. In a 1969 case, the justices held that a Vietnam War protester did not make a knowing and willful threat against the president when he remarked that "If they ever make me carry a rifle the first man I want to get in my sights is L.B.J," referring to President Lyndon B. Johnson. The court noted that laughter in the crowd when the protester made the statement, among other things, showed it wasn't a serious threat of violence.

Regarding the current case, Merriam-Webster, the dictionary used by The Associated Press, says 86 is slang meaning "to throw out," "to get rid of" or "to refuse service to." It notes: "Among the most recent senses adopted is a logical extension of the previous ones, with the meaning of 'to kill.' We do not enter this sense, due to its relative recency and sparseness of use."

Comey deleted the post shortly after it was made, writing: "I didn't realize some folks associate those numbers with violence" and "I oppose violence of any kind so I took the post down."

What the government will try to prove

John Fishwick, a former U.S. attorney in the Western District of Virginia, said the government will likely try to prove that Comey should have known better as a former FBI director.

"I think they're going to try to circumstantially say that you were head of the FBI, you knew what these terms meant and you said them out to the whole world as a threat to the president," Fishwick said, though he noted that such an argument would be challenging in light of Comey's obvious First Amendment defenses.

Comey was voluntarily interviewed by the Secret Service last year, and the fact that he was not charged with making a false statement suggests that prosecutors do not have evidence that he lied to agents Fishwick said.

Jonathan Turley, a George Washington University law professor, wrote in an opinion piece published Tuesday that "despite being one of Comey's longest critics, the indictment raises troubling free speech issues. In the end, it must be the Constitution, not Comey, that drives the analysis and this indictment is unlikely to withstand constitutional scrutiny."

"If it did," he added, "it would allow the government to criminalize a huge swath of political speech in the United States."

Kunzelman reported from Alexandria, Va.