The FBI said the man charged in the attack in Boulder, Colorado, that left eight people injured told police he planned it for a year and specifically targeted what he described as the "Zionist group."
An FBI affidavit says Mohammed Soliman confessed to the attack after being taken into custody Sunday and told the police he would do it again.
The affidavit was released in support of a federal hate crime charged filed by the Justice Department on Monday.
The group that was targeted had gathered in a popular pedestrian park in Boulder to draw attention to the Israeli hostages who remain in Gaza.
The burst of violence at the popular Pearl Street pedestrian mall, a four-block area in downtown Boulder, unfolded against the backdrop of a war between Israel and Hamas that continues to inflame global tensions and has contributed to a spike in antisemitic violence in the United States.
The attack happened on the beginning of the Jewish holiday of Shavuot, which is marked with the reading of the Torah and barely a week after a man who also yelled "Free Palestine" was charged with fatally shooting two Israeli embassy staffers outside of a Jewish museum in Washington.
Israeli Prime Minister Benjamin Netanyahu issued a statement Monday saying he, his wife and the entire nation of Israel were praying for the full recovery of the people wounded in the "vicious terror attack" in Colorado.
"Sadly, attacks like this are becoming too common across the country," said Mark Michalek, the special agent in charge of the FBI’s Denver field office, which encompasses Boulder.