Grewell noted the suspect used Molotov cocktails after being unable to purchase a gun for the attack.

FBI Special Agent-in-Charge for Denver Mark Michalek said authorities found 16 unused Molotov cocktails on Soliman. He credited the police's quick response with preventing the suspect from using the additional fire bombs.

Soliman was not on the police’s "radar" before the attack, Redfearn said. "This is not someone we were aware of."

Suspect says he learned to make Molotov cocktails from the Internet

Soliman is a married father of five who told investigators he learned how to make Molotov cocktails from the Internet and ranted about protecting Palestine, the FBI said.

According to investigators, Soliman had been planning the attack for a year and bought 87-octane gasoline the day of the attack as he drove from his home in Colorado Springs to Boulder, about 100 miles north. The FBI said investigators found 14 unused Molotov cocktails in a plastic bin near where police detained Soliman, along with a weed sprayer loaded with gas.

Investigators said Soliman disclosed he had left at home an iPhone containing messages to his family, along with a journal. Investigators did not immediately release any details of those messages or the journal's contents.

Soliman is being held on a $10 million bond at the Boulder County Jail and is accused of throwing two lit glass bottles of gas at the protesters.

"Throughout the interview, Soliman stated that he hated the Zionist group and did this because he hated this group and needed to stop them from taking over 'our land,' which he explained to be Palestine," FBI agent Jessica Krueger said in an affidavit. "He stated that he had been planning the attack for a year and was waiting until after his daughter graduated to conduct the attack."

Soliman entered the United States on a tourist visa in 2022

Soliman, of El Paso County, Colorado, was taken into custody after witnesses pointed him out, authorities said. He was booked on multiple preliminary charges, including first-degree murder and using explosives or an incendiary device while committing a felony.

Police said Soliman was injured in the incident and taken to a hospital to be medically evaluated before he was booked in the Boulder County jail. Stephen Miller, President Donald Trump's deputy chief of staff, said Soliman overstayed a tourist visa issued in 2022.

"In response, the Biden administration gave him a work permit," Miller said in a social media post. "Immigration security is national security. No more hostile migration. Keep them out and send them back."

CBS News and Fox News, citing unnamed sources, reported that Soliman is an Egyptian national. FBI agents searched Soliman's home in El Paso County hours after the attack, the agency's field office in Denver said on X.

Soliman worked for Uber, company says

Uber confirmed on Monday that Soliman had worked as a driver starting in spring 2023. The company did not specify whether he worked driving passengers or for Uber Eats, or both. 

In a statement to USA TODAY, the company said his account has been terminated, prohibiting him from working there again. The company noted that he passed a background check and provided the legally required documents necessary to work as a contractor.

“Mr. Soliman had no concerning feedback while driving on the Uber platform,” the company said in a statement. “We’ve banned the driver’s account and have been in touch with law enforcement.”

Trump blames Biden administration border policies

Trump on Monday cited Soliman as another reason to "deport illegal, anti-American radicals" from the U.S.

"Yesterday’s horrific attack in Boulder, Colorado, WILL NOT BE TOLERATED in the United States of America," Trump said in a social media post. "He came in through Biden’s ridiculous Open Border Policy, which has hurt our Country so badly. He must go out under “TRUMP” Policy. Acts of Terrorism will be prosecuted to the fullest extent of the Law."

'We are shaken': Jewish Community Center tightens security

Four miles from the scene of the attack, security was extra tight at the sprawling Boulder Jewish Community Center campus, where outdoor summer camp programs were being held under the watch of both police and armed private security. The JCC serves as a central hub for many area Jewish residents, and security guards are a regular presence.Staff at the JCC said they are still discussing how to best honor the victims of the attack and declined to comment publicly.

"When events like this enter our own community, we are shaken. Our hope is that we come together for one another," center officials said in a social media post. "Strength to you all."

Attack comes after Israeli Embassy staffers were fatally shot

The attack fell on the Jewish holiday of Shavuot and came less than two weeks after two Israeli Embassy aides were fatally shot outside a Jewish museum in Washington, D.C.

Yaron Lischinsky and his girlfriend, Sarah Lynn Milgrim, were shot after a Young Diplomats reception hosted by the American Jewish Committee.

The suspect in that attack, Elias Rodriguez, 31, chanted "Free Palestine, free Palestine," after being taken into custody by event security. He is charged with a long list of crimes, including federal and local murder charges and the murder of foreign officials.

The May 21 shooting is being investigated as a hate and terrorism crime.

FBI pledges 'preventative action' to protect Americans

The Boulder attack occurred at a "regularly scheduled, weekly, peaceful event," FBI Denver Special Agent in Charge Mark Michalek said. Anyone with videos, social media posts or digital recordings was asked to upload them at www.fbi.gov/boulderattack.

“We stand in full solidarity with those targeted,” Michalek said. “We will continue to ensure that justice is pursued swiftly, support is provided to victims and their communities, and preventative action is taken to protect everyone’s safety.”

Netanyahu cites 'blood libels against the Jewish state'

Israeli Prime Minister Benjamin Netanyahu on Monday expressed solidarity with the victims who were attacked "simply because they were Jews. " He said he was confident U.S. authorities would prosecute "the cold-blood perpetrator to the fullest extent of the law."

"The antisemitic attacks around the world are a direct result of blood libels against the Jewish state and people, and this must be stopped," Netanyahu said in a statement.

What is a B-2 visa?

Soliman was in the United States on a B-2 tourism visa, according to Department of Homeland Security Assistant Secretary Tricia McLaughlin. A B-2 visa is generally used for tourism and is issued by the State Department. In general, the visas are valid for six months and can be used for vacations, visiting relatives, medical treatment or participation in music, sports or events.

The State Department issues millions of B-1 and B-2 visas each year. B-1 visas are similar to B-2 and allow for nonimmigrants to visit for six months for conferences and business reasons.

Soliman entered the United States in August 2022 and his visa expired in February 2023. In addition, McLaughlin wrote on X that Soliman applied for asylum in 2022. That claim was likely still pending. As of March, the immigration court backlog was around 3.6 million cases, according to the Transactional Records Access Clearinghouse at Syracuse University. 

− Nick Penzenstadler

Holocaust survivor among the wounded

Rabbi Israel Wilhelm, the Chabad director at the University of Colorado Boulder, told CBS Colorado the 88-year-old victim is a Holocaust refugee who fled Europe. Wilhelm described the woman as a "very loving person."

Chany Scheiner, a friend of the victim, told KUSA-TV the woman is an “amazing."

"She has spoken at our synagogues as well as other synagogues and schools just about her background and the Holocaust and from her own perspective,” Scheiner said. “Her life wasn’t easy, but she is just a bright light. And anybody who is her friend is a friend for life.”

Antisemitic hate crimes on the rise in the U.S.

The incident comes amid heightened tensions in the U.S. and around the world over Israel's military campaign in Gaza. The war has dragged on for 20 months, since the Hamas attack on Israeli border communities that killed about 1,200 people, mostly civilians, and saw more than 250 others dragged across the border into Gaza as hostages.

The conflict has fueled antisemitic hate crime in the U.S. Reports of incidents of antisemitism rose for a second year in a row in 2024, according to an annual report released by the Anti-Defamation League in April.

The controversy also has prompted supporters of Israel, including Trump, to brand peaceful, pro-Palestinian protests as antisemitic.

Who is Mohamed Soliman? FBI raids home of suspect in Colorado terror attack

Contributing: Thao Nguyen, Susan Miller, Bart Jansen, and Michael Collins, USA TODAY; Reuters

(This story was updated to add new information.)