One of shooters in deadly attack at San Diego mosque was previously flagged by FBI

One of the two white supremacist shooters who attacked a mosque in California on Monday and killed three people had already been on law enforcement officials’ radar, according to US media reports.

Local officials were so alarmed by Caleb Vazquez’s idolization of mass shooters and Nazism that they seized his father’s guns a year before the shooting, the New York Times reports. Similarly, Bloomberg reports that Vazquez had already been flagged by the FBI as a “potential threat” last year.

Eighteen-year-old Vazquez and his friend, Cain Clark, 17, attacked the Islamic Center of San Diego earlier this week and killed three men, including a security guard who exchanged gunfire with the attackers and prevented them from reaching 140 schoolchildren. The two shooters then died from self-inflicted gunshot wounds in their getaway car.

The Associated Press reported this week that the two shooters were radicalized online, where they first met, and shared white supremacist and pro-Nazi views. In addition to calling for Muslims to be “exterminated”, the pair also expressed hatred towards Jewish people, the LGBTQ+ community, Black people and women.

Online materials purportedly written by Vazquez and reviewed by the Guardian show he had a far-right and white supremacist “accelerationist” ideology that promoted extreme violence. NPR reported the San Diego shooting shared alarming similarities with the 2019 Christchurch mosque massacre in New Zealand that killed 51 people.

Vazquez was already on law enforcement’s radar, after someone flagged to officials troubling social media posts. In a protective order last year, a police officer wrote that Vazquez was involved in “suspicious behavior” that idolized Nazis and mass shooters, prompting officials to seize Vazquez’s father’s guns. Vazquez had also been placed in an involuntary psychiatric hold, the Times reported.

Vazquez’s father and his wife had 26 guns, including pistols, rifles and shotguns in their home. The father wrote in an affidavit that he had voluntarily put the weapons in a storage facility because of concerns about his son. The court ordered him to voluntarily turn over his guns to officials.

Officials said that they found at least 30 guns, ammunition and a crossbow at two separate residences after Monday’s attack. It is unclear if the weapons involved in the shooting came from the Vazquez home, since officials said Clark also grew up with guns.

After the shooting, the Vazquez family apologized for their son’s actions in a statement provided by an attorney, blaming his autism diagnosis and online radicalization. The family said they “stand firmly against the ideology and actions that led to this tragedy”. They also apologized to the families of the three people who were killed.

On Monday, both shooters arrived at the Islamic Center of San Diego and tried to barge inside, prompting a security guard to open fire and forcing them back outside. As the three engaged in gunfire, the guard called for a lockdown.

The shooters were able to enter the lobby and fatally shot the guard, but were unable to reach anyone in the mosque’s rooms because they were emptied during the lockdown. The shooters then exited into the parking lot and fatally shot two other men who worked with the mosque. The men had drawn the attackers away from the building, officials said this week.

The mosque’s imam said this week that the community had been the subject of hate mail and messages in the past.