Mohamed Sabry Soliman, a 45-year-old Egyptian national, carried out a firebomb attack at a pro-Israel rally in Boulder, Colorado.
Armed with a homemade flamethrower and petrol bombs, he injured eight Jewish-Americans, including a Holocaust survivor.
Soliman had entered the US on a B1/B2 visa in August 2022 via LAX, but overstayed.
He later received work authorisation under the Biden administration, which expired in March 2025.
Witnesses said he shouted “Free Palestine” during the attack.
The FBI is treating the incident as an act of terror. Soliman is in custody.
Authorities say the victims were marching for hostages held by Hamas.