Federal prosecutors charge Ryan Routh with attempted assassination of Donald Trump
He is expected to be arraigned next week.
WEST PALM BEACH, Fla. -- Federal prosecutors have officially charged Ryan Routh with attempting to assassinate former President Donald Trump, a source familiar with the matter confirmed to ABC News.
The move was expected and previewed both by prosecutors in a court hearing on Monday and by Attorney General Merrick Garland in a news conference Tuesday afternoon.
The charging documents have not yet been officially updated on Routh's court docket. He is expected to be arraigned on the charges in a court hearing next week.
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Judge Aileen Cannon, the Trump-appointed judge who threw out Trump's classified documents case, has been randomly assigned to oversee the Ryan Routh case, according to sources familiar with the matter.
Routh, 58, had previously been charged with possession of a firearm as a convicted felon and possession of a firearm with an obliterated serial number for the incident that took place at Trump International Golf Club on Sept. 15.
On Monday, prosecutors outlined new details about their investigation and said there is "probable cause to support additional charges which can and should be considered by the court."
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Routh possessed a list that included dates from August to October of venues where Trump had appeared or was expected to be -- and is suspected to have traveled near the golf course and Trump's Mar-a-Lago resort multiple times in the month leading up to his arrest, prosecutors said in a detention filing.
In their memo, prosecutors further revealed that Routh allegedly sent a letter "several months prior" to his arrest to a civilian witness that stated, "This was an assassination attempt on Donald Trump but I failed you."
The government argued the sole reason Routh was in West Palm Beach on Sept. 15 and the proceeding month was "for one reason and one reason only and that was to kill the former President of the United States."
RELATED: Apparent assassination attempt | Suspect never had Trump in sight, did not get off shot: Officials
On the day of the attempted assassination, Trump was playing golf on the course when a Secret Service agent spotted a gun barrel poking out from the tree line near the sixth green, according to investigators.
The agent then fired in the direction of the rifle and saw Routh fleeing the area and entering his nearby vehicle, according to the criminal complaint filed in the case.
In the area of the tree line where the suspect was seen, agents found a digital camera, two bags, including a backpack, and a loaded SKS-style 7.62x39 caliber rifle with a scope, according to the complaint.
Trump was not harmed in the incident and was taken to a safe location by Secret Service agents.
-- ABC News' Katherine Faulders and Aaron Katersky contributed to this report.
This is a developing story. Please check back for updates.
