Federal prosecutors have charged the man who was spotted with a gun outside of Donald Trump's golf course with attempted assassination of a presidential candidate.

The indictment, unsealed Tuesday, alleges that Ryan Wesley Routh "did intentionally attempt to kill Former President of the United States Donald J. Trump, a major Presidential candidate" when he was camped out near where Trump was golfing on Sept. 15 in West Palm Beach, Florida. The charges carries a maximum penalty of life in prison if convicted.

It also added two other charges: possessing a firearm in furtherance of a crime of violence and assaulting a federal officer.

Routh had previously been charged with possession of a firearm by a convicted felon and possession of a firearm with an obliterated serial number.

The case has been assigned to U.S. District Judge Aileen Cannon, the Trump nominee who dismissed the criminal classified documents against the former president earlier this year.

The Justice Department said the a grand jury in Miami returned the indictment with the additional charges late Tuesday afternoon.

The indictment comes one day after Trump issued a statement accusing the Justice Department of “downplaying” the alleged assassination plot against him this month and suggesting state officials in Florida take over the case.

“The Kamala Harris/Joe Biden Department of Justice and FBI are mishandling and downplaying the second assassination attempt on my life since July. The charges brought against the maniac assassin are a slap on the wrist,” Trump said in a statement Monday, alleging they have a conflict of interest “since they have been obsessed with ‘Getting Trump’ for so long.”

Federal prosecutors had indicated during Routh's court appearance Monday that other charges were coming. Among the additional evidence they said they'd collected was a handwritten note from Routh addressed to "The World" that said, “This was an assassination attempt on Donald Trump but I failed you.”

Routh, 58, of Hawaii, has been ordered held without bail pending trial. He has not yet been arraigned.

In a statement Tuesday, U.S. Attorney General Merrick Garland said, “Violence targeting public officials endangers everything our country stands for, and the Department of Justice will use every available tool to hold Ryan Routh accountable."

"This must stop," Garland said.

Trump was the victim of an assassination attempt in Butler, Pa., in July. The gunman was killed by Secret Service after opening fire on Trump, with a bullet hitting his right ear, at a campaign rally.