Trump on Charlie Kirk's killer: 'He became radicalized on the Internet in a very short time'
The president noted that the process of radicalization to the left via the internet marked a break in the behavior of the main suspect, Tyler Robinson.

The arrest photo of Tyler Robinson, suspect in the murder of Charlie Kirk
President Donald Trump addressed a press conference on Monday on the murder of conservative activist Charlie Kirk, a crime that has shocked the United States and that began to be solved in recent days with the capture of the main suspect, Tyler Robinson. When asked by a reporter whether the attacker acted alone, Trump said he could not confirm, but added that it did seem clear that Robinson was radicalized online in a surprisingly short span.
"I don’t know. I I mean, I can tell you he didn’t work alone on the Internet because it seems that he became radicalized on the Internet. That’s just by watching what same things that you’re watching and hearing. It looks like he became radicalized over the Internet. And it seems like he has wonderful parents born in a wonderful neighborhood, smart guy, great boards, great marks, great student. And then he, something happened to him over a fairly short period of time. Looks like he was radicalized over the Internet, and it’s radicalized on the left," Trump declared.
Reporter: “I’m wondering if you think Charlie Kirk’s assassin worked alone?”@POTUS “It seems that he became radicalized on the internet…” pic.twitter.com/jJdThhcjqU
— Margo Martin (@MargoMartin47) September 15, 2025
The president subsequently insisted that the attacker's profile did not seem to match the classic shooter, as he came from a stable family, had a favorable environment and was a good student. However, the president pointed out that the process of radicalization towards the left through the internet marked a break in his behavior.
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Antifa and the application of the RICO Act
Then, in another part of the conference, Trump responded to a query about "left-wing violence" and whether he planned to designate the extremist group Antifa as a domestic terrorist organization. The president said he would be willing to do so "100 percent" if he has sufficient backing, advancing that similar measures against other groups he described as "radical" are also being evaluated.
"Well, it's something I would do. Yes. If I have support from the people here, I think I would start with Pam, I think. But I would — if you ask me, I would do that a hundred percent, and others also, by the way. But Antifa is terrible," Trump said.
The president added that he has discussed with the attorney general the possibility of applying the RICO Act against individuals and organizations that finance acts of violence, stating that vandalisms "aren't protests. These are crime." He described, pointedly, scenes of brick attacks on ICE and Border Patrol vehicles, and criticized previous administrations for ordering law enforcement "not to respond" to direct assaults.
"They were told, by a past administration, that it became almost a culture. If somebody throws a rock at you, do nothing. If somebody spits in your face, do nothing. And I say: when they spit, you hit back. Do whatever you want. Do whatever the hell you want," he lashed out.
The president, finally, closed his speech by accusing millionaire organized groups of paying professional agitators to generate chaos in public events and restaurants. He insisted that such practices are "subversive" against the U.S. and should be punishable by imprisonment through criminal prosecutions under RICO.
REPORTER: Do you plan on designating Antifa a domestic terror organization?@POTUS: "It's something I would do, yeah... and also, I've been speaking to @AGPamBondi about bringing RICO against some of the people... that have been putting up millions and millions of dollars for… pic.twitter.com/eAuK3nXKVh
— Rapid Response 47 (@RapidResponse47) September 15, 2025