The Federal Bureau of Investigation is working to determine how a man with an assault rifle got within a few hundred yards of former President Donald Trump in what law enforcement is calling an apparent assassination attempt.

The incident unfolded on at Trump International Golf Club in Florida on Sunday, when a Secret Service agent spotted a rifle barrel poking through a chain link fence just ahead of where Trump was playing. The agent took action and fired about four to six rounds, though it is unclear if the suspect managed to fire any shots.

The suspect has been identified as 58-year-old Ryan Wesley Routh.

Routh is a construction company owner from Hawaii who volunteered to fight for Ukraine in its war with Russia. In a self-published book last year, Routh called Trump “an idiot, a buffoon, and a fool.”

In 2002, the Greensboro News & Record reported Routh barricaded himself inside a roofing business during a three-hour standoff with police. Routh was hit with several charges in the incident, including possession of a weapon of mass destruction, which was a fully automatic machine gun.

The golf course incident has authorities questioning security arrangements for Trump's frequent golf outings and his public appearances.

Routh is due in court on Monday.

Florida Gov. Ron DeSantis also said the state is launching its own investigation into the incident.

"The State of Florida will be conducting its own investigation regarding the attempted assassination at Trump International Golf Club," DeSantis said on X.

"The people deserve the truth about the would be assassin and how he was able to get within 500 yards of the former president and current GOP nominee," he said.

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Trump was not hurt in the second apparent assassination attempt against him in just nine weeks.

He took to social media Sunday night to thank the Secret Service and other law enforcement officers for keeping him safe.

"I would like to thank everyone for your concern and well wishes — it was certainly an interesting day!" Trump wrote on Truth Social. "Most importantly, I want to thank the U.S. Secret Service, Sheriff Ric Bradshaw and his office of brave and dedicated patriots, and, all of law enforcement, for the incredible job done today at Trump International in keeping me, as the 45th President of the United States, and the Republican nominee in the upcoming Presidential Election, SAFE. THE JOB DONE WAS ABSOLUTELY OUTSTANDING. I AM VERY PROUD TO BE AN AMERICAN!”

President Joe Biden commended the Secret Service and law enforcement for keeping Trump safe and condemned political violence.

“As I have said many times, there is no place for political violence or for any violence ever in our country, and I have directed my team to continue to ensure that Secret Service has every resource, capability and protective measure necessary to ensure the former president’s continued safety,” President Biden said in a statement on X.

Vice President Kamala Harris also spoke out.

“I am deeply disturbed by the possible assassination attempt of former President Trump today. As we gather the facts, I will be clear: I condemn political violence. We all must do our part to ensure that this incident does not lead to more to violence,” Harris said in a statement posted to social media.

“I am thankful that former President Trump is safe. I commend the U.S. Secret Service and law enforcement partners for their vigilance,” she said. “As President Biden said, our administration will ensure the Secret Service has every resource, capability and protective measure necessary to carry out its critical mission.”

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