Ryan Wesley Routh, 58, appeared in prison scrubs and shackles at a federal courthouse in the U.S. District Court for the Southern District of Florida.

Routh is charged with possessing a firearm despite being a convicted felon and possessing a firearm with a destroyed serial number, according to charging documents. He will be detained without bond until at least Sept. 23, when the court scheduled a detention hearing. He faces up to 20 years in prison if convicted.

Authorities say Routh waited in the bushes, armed with an AK-47-style rifle, to shoot Trump on Sunday while the former president was playing golf a few hundred yards away at Mar-a-Lago.

Trump was unharmed during the incident. The Secret Service observed Routh and fired shots at him, leading Routh to take off, and law enforcement officials later located and detained him, authorities said.

An abundance of details about Routh and his probable motive emerged soon after the incident.

The suspect appeared to be a political ideologue with a large social media presence who became disenchanted with Trump after 2016. Routh appeared to shift his favor toward various Democrats in recent years and developed a fixation on supporting Ukraine in 2022.

Routh wrote a digital book called Ukraine’s Unwinnable War that became available on Amazon in 2023. In it, Routh repeatedly criticized Trump and expressed a desire for him to be assassinated.

“I must take part of the blame for the retarded child that we elected for our next president that ended up being brain-less, but I am man enough to say that I misjudged and made a terrible mistake and Iran I apologize,” Routh wrote. “You are free to assassinate Trump as well as me for that error in judgement and the dismantling of the [Iran nuclear] deal.”

Routh also wrote that “no one here in the US seems to have the balls to put natural selection to work or even unnatural selection.”

He described Trump at times as an “idiot” and a “fool” and wrote that the Jan. 6 Capitol riot was an incident “perpetuated by Donald Trump and his undemocratic posse.”

Routh was also active on X, posting frequently before his account was suspended. In one now-unavailable X post, Routh said he voted for Trump in 2016 but that the former president seems to be “getting worse and devolving.”

In another, he encouraged Nikki Haley and Vivek Ramaswamy, who ran in the Republican presidential primary, to “partner now to change the course of this election.”

The FBI, which is leading the inquiry into Routh, announced after the incident on Sunday that it was investigating “what appears to be an attempted assassination” of Trump.

This story is developing and will be updated.