The man who was arrested in Boulder, Colo., for throwing Molotov cocktails at people attending a march in support of Israeli hostages in Gaza was charged today with a federal hate crime.

Authorities said the man yelled “Free Palestine” during the attack. Twelve people were injured, including eight who were hospitalized with burns, officials said. Witnesses described “horrible” scenes.

The F.B.I. said the man, Mohamed Sabry Soliman, told investigators that he had been planning the attack for a year and that he wanted to “kill all Zionist people and wished they were all dead.” Police said he had brought more than a dozen incendiary devices to the event and disguised himself as a gardener in order to get as close as possible to the marchers.

Soliman, who is 45, entered the U.S. from Egypt in 2022 and stayed illegally after his visa expired in 2023. He told a detective that he used Molotov cocktails in the attack because he had not been able to buy a gun.

The attack has deepened anxieties among many American Jews, coming less than two weeks after a couple was fatally shot outside the Capital Jewish Museum in Washington, D.C.

For more: Here’s what we know about the attack.