Alleged Trump gunman 'wrote of assassination attempt'

A man accused of hiding out with a gun near Donald Trump's Florida golf course in an apparent bid to kill the former US president wrote a letter months earlier describing an "assassination attempt" and offering a bounty on Trump's life, US prosecutors say.

Ryan Routh, 58, has been charged with two gun crimes after he allegedly pointed a rifle through the tree line on September 15 while the Republican presidential candidate was playing golf at his course in West Palm Beach, according to a criminal complaint.

He has not yet entered a plea.

Routh is due to appear at a hearing scheduled for later on Monday in which prosecutors will ask a judge to keep him in jail until his trial.

In a court filing released before the hearing, prosecutors said that several months prior to the incident, Routh dropped off a handwritten letter addressed to "the world" that offered a bounty on Trump.

"This was an assassination attempt on Donald Trump but I failed you," the suspect wrote, according to the filing.

"I will offer $US150,000 to whomever can complete the job."

The letter was found in a box handed over by an unidentified civilian witness that also included ammunition, a metal pipe and four phones, prosecutors said.

Prosecutors also said that when Routh was arrested this month his car contained a handwritten list of dates in August, September and October of places where Trump had appeared or was expected to appear.

They said a search of his mobile phone records showed that the devices had pinged towers near the Trump International golf course where the incident took place and by the Mar-a-Lago resort where Trump lives.

Routh has been charged with possession of a firearm as a convicted felon and possession of a firearm with an obliterated serial number.

More charges could follow.

A US Secret Service agent spotted the weapon and fired in Routh's direction, causing the suspect to flee, according to the complaint.

Routh was later arrested along a Florida highway.

US officials have said Routh did not fire a shot during the encounter at the golf course and did not have a line of sight to Trump, who was a few hundred metres away.

Authorities have not yet divulged a motive for the incident, which the FBI has said is being investigated as an apparent attempted assassination of Trump ahead of the November 5 presidential election.

It came about two months after another gunman wounded Trump on the ear during a campaign rally in Butler, Pennsylvania.

That gunman was shot and killed by the Secret Service.

The pair of incidents revealed the agency's strains at a time of rising political threats and violence in the United States.

Routh, a struggling roofing contractor who most recently lived in Hawaii, had a criminal history.

He was a vocal supporter of Ukraine who was interviewed about his quixotic effort to recruit Afghans to fight against Russia's invasion.

In a 2023 self-published book, Routh wrote that Iran was "free to assassinate Trump" for pulling the United States out of an international nuclear deal with Iran during his presidency.

In December 2002, Routh was convicted in North Carolina of possessing a weapon of mass death and destruction.

He was also convicted of possessing stolen goods in 2010, according to court records.

Mobile phone data showed that Routh may have been waiting in the area for nearly 12 hours - from about 2am until about 1.30pm - when the gun was spotted, according to the criminal complaint.

Investigators found a loaded SKS-style rifle with a scope, a digital camera and a plastic bag with food at the scene, according to the complaint.