Two teenage gunmen killed three people at a San Diego mosque Monday, authorities said.

Investigators are working to determine the motivation of the attackers, who are believed to have later died of self-inflicted gunshot wounds, but San Diego’s police chief said the violence was being investigated as a possible hate crime.

Investigators are trying to authenticate a document filled with extremist material posted online espousing anti-Islamic, antisemitic and anti-LGBTQ views that purportedly details their motivations, three senior law enforcement officials said.

Police Chief Scott Wahl said the event was “every community’s worst nightmare.”

Here’s what we know about the shootings.

The victims

The three men killed in the attack at the Islamic Center of San Diego, described on its website as the largest mosque in San Diego County, were identified as Amin Abdullah, Mansour Kaziha and Nader Awad.

Abdullah, an armed security guard at the mosque, was hailed as hero for having “delayed, distracted and ultimately deterred” the suspects from targeting nearby areas of the mosque where there were as many 140 kids, Wahl said Tuesday.

During a gun battle with the suspect outside the center, Abdullah was struck but continued to fire at the shooters, Wahl said. Security video reviewed by law enforcement showed that after Abdullah was shot, he reached for his radio and implemented a lockdown protocol for the building, Wahl said.

The video showed the suspects entering the mosque and moving from room to room, Wahl said, but by then, others in the building had found safe locations to hide.

Kaziha and Awad were in the parking lot, where they inadvertently drew the shooters’ attention, Wahl said. Video showed the shooters point at the men through a window, then run outside and “immediately engage” Kaziha and Awad, Wahl said.

When authorities responded to a 911 call at the mosque shortly before noon, Wahl said, they found all three men dead outside the building.

An imam with the mosque, Taha Hassane, said Kaziha, a longtime cook, handyman and caretaker at the Islamic center, was the first at the center to dial 911.

“He was everything,” Hassane said. “I don’t know what I’m going to do at the Islamic Center without his assistance.”

Awad’s wife is a teacher at an Islamic school at the mosque, Hassane said, and Awad was a constant presence there.

“When he heard the shooting, he rushed to do something to protect,” Hassane said. “He joined Mansoor Kaziha. They died together.”

Where were the suspects found?

As police officers deployed what Wahl described as an active shooter response at the mosque and an adjacent school, more gunfire was reported blocks away, he said.

A landscaper who was working in the area was shot at but not struck, Wahl said.

Less than a quarter-mile from the landscaper, police found a vehicle in the middle of the street with the two teenagers believed to be the shooters inside, Wahl said.

Both are believed to have died by self-inflicted gunshot wounds, he said.

Two senior law enforcement officials briefed on the investigation and a federal law enforcement official identified the suspects as Cain Clark, 17, and Caleb Vazquez, 18.

Clark attended high school virtually and was set to graduate this month, according to a school district official.

He also participated on the school’s wrestling team while he studied virtually, as Madison would be his high school if he decided to attend, the official said. Clark was on the team for the 2024-25 season.

The mother of one of the suspects called police Monday morning and said her son, her firearms and her car were missing, Wahl said.

She described the teen as suicidal and said he was most likely with a friend, Wahl said. Both were “dressed in camo,” he recalled her saying.

Officers were talking with the woman and trying to piece together where her son might be when they learned what was happening at the Islamic center, Wahl said.

Initially, police followed leads to a nearby mall, then connected one of the suspects to Madison High School. San Diego officials alerted school police before they received the call about the mosque.

They then “immediately dispatched themselves to the mosque,” he said.

An FBI official, Mark Remily, said investigators have recovered more than 30 guns, ammunition and tactical gear after they executed search warrants at homes linked to the suspects.

The guns used in Monday’s attack belong to one of their parents, Wahl said. How the teens obtained the weapons remains under investigation, he said.

What we know about a possible motive

Wahl said “hate rhetoric” was involved in the shooting. Investigators are examining possible anti-Islamic writings found in the teens’ car, two senior law enforcement officials said.

Three senior law enforcement officials said investigators are also trying to authenticate a 75-page document posted online that purportedly details the teens’ motives.

The writings are filled with extremist material espousing anti-Islamic, antisemitic and anti-LGBTQ views, the officials said. The authors refer to accelerationism, a white supremacist ideology that promotes violence to speed the formation of a white ethnostate, and they describe the man who carried out a horrific mass shooting at a New Zealand mosque as a “hero.”

Remily said investigators are analyzing a manifesto to learn more about the circumstances of Monday’s violence and to prevent future attacks.

“These subjects did not discriminate on who they hated,” Remily said.

A rattled community

The Monday shooting has rattled the Muslim community both in Southern California and across the U.S., prompting some officials to call for an end to what they call a “campaign of hate” from mainstream politicians.

San Diego Mayor Todd Gloria called the shooting a “violent act of hate” and urged the city to unite against Islamophobia.

The California chapter of the Council on American–Islamic Relations, a civil rights and advocacy group, said in a statement that the shooting was directly linked to comments made by lawmakers with national standing.

“We are deeply disturbed, but not at all surprised, to learn that those who attacked the Islamic Center of San Diego were reportedly motivated by anti-Muslim hate,” said Hussam Ayloush, the CEO of CAIR’s California chapter.

Hassane, the imam at the Islamic Center, said the shooting was unprecedented, but he placed it within a recognizable pattern of intolerance.

“This is something that we have never expected to take place, but at the same time the religious intolerance and the hate, unfortunately, that exists in our nation is unprecedented,” he said. “All of us, we are responsible for spreading the culture of tolerance, the culture of love.”

Multiple Republican politicians posted anti-Muslim messages to their social media accounts this year after the U.S. and Israel launched their war against Iran.