San Diego mosque shooter Cain Clark left a hate-filled suicide note 'about racial pride' before opening fire and killing three people, authorities say.
Clark, 17, attacked the Islamic Center of San Diego alongside Caleb Vazquez, 18, around 11:40am on Monday, after stealing guns and a car from his mother's home.
Hours before the attack, Clark's mother reported to police that her son had he was suicidal and potentially armed with her weapons, and officers were already searching for the teen when he opened fire.
After killing three people, Clark and Vazquez were found near the mosque with self-inflicted gunshot wounds, and police said one of the guns in their vehicle had 'hate speech' written on it, sources told the LA Times.
Police sources told the outlet that when officers searched Clark's home around two miles from the mosque, they also discovered a suicide note 'writing about racial pride.' A BMW X1 that the two shooters died in was photographed with a gas can emblazoned with a Nazi SS sticker on its side.
Clark was enrolled in a virtual learning academy at the San Diego Unified School District, and was set to graduate from high school this semester, school officials said.
He was previously a star wrestler at Madison High School, but had only been attending classes online for some time, as officials said he had spiraled into 'hate speech.'
Clark's grandparents David and Deborah Clark told CNN they have been left stunned and heartbroken by the tragedy, saying they were 'trying to process this' and were 'very sorry for what happened.'
Cain Clark, 17, was one of two teenagers who opened fire at a California mosque on Monday before taking his own life. Police named the other suspect as Caleb Vazquez, 18, who has not yet been pictured
Images from the scene where the teens were found dead showed a red gasoline canister with a sticker resembling a Nazi SS logo, as a shotgun lay nearby
San Diego Police Chief Scott Wahl said on Monday that hours before the tragedy, his department got a call from the teenager's mom who was concerned he was suicidal.
The mom, who has not been named, said she realized several of her guns were missing, and said she saw him and a companion wearing 'camouflage outfits', Wahl said.
Wahl said that although Clark's mother warned cops that her weapons were missing, she did not indicate any kind of planned attack on the mosque.
'There was no specific threat, especially no specific threat to the Islamic Center,' the police chief said.
'It was just general hate kind of speech that I think covered a wide gamut.'
Police said they arrived at the Islamic Center within minutes of the shooting, and found three people deceased in front of the building, including security guard Amin Abdullah, who was hailed as a hero as he saved lives during the chaotic shooting.
Several blocks away, a landscaper was also shot at but was not hit, and minutes later police received a call about shots fired down the street.
Clark and Vazquez were found dead inside a vehicle on Salerno Street, several streets away from the Islamic Center.
Images from the scene showed a red gasoline canister with a sticker resembling a Nazi SS logo, as a shotgun lay nearby.
While authorities and police sources have revealed some details of Clark, little is known about Vazquez.
Amin Abdullah, a father of eight, was among those killed in the rampage
Authorities are now probing the shooting as a hate crime. An officer is seen at one of the shooting suspect's homes on Monday evening
When the teens opened fire, witness Vanessa Chavez told The New York Times she watched in horror as the security guard was struck by at least two gunshots while children playing outside were herded into the building.
As many as 100 officers then combed the mosque for any signs of the shooters, breaking down doors as they evacuated the Al Rashid school on campus, which serves students in kindergarten through third grade.
But the teens had already fled the scene, also shooting at a landscaper working on a nearby home as they made their escape.
As authorities now probe the shooting as a hate crime, they are looking into reported anti-Islamic writings that were found inside the vehicle where the boys were found dead.
The shooting at the San Diego Islamic Center came at the beginning of Dhu’l-Hijja, one of the holiest months on the Muslim calendar.
It translates to 'month of the pilgrimage' and marks a time when millions of Muslims across the world embark on the Hajj, an annual pilgrimage to Mecca in Saudi Arabia.
The Islamic Center of San Diego is the largest mosque in San Diego County, with around 5,000 members.
Officers arrived on the scene in just four minutes, as they had already been searching for the teenagers after one of their mothers alerted cops to the threat
The Council on American-Islamic Relations demanded politicians end their 'campaign of hate' following the deadly shooting
Neighbors raced to the scene of the mosque after the shots were fired
Although authorities have not yet established a motive, the attack on the religious center sparked concerns over Islamophobia among local officials.
San Diego Mayor Todd Gloria said in a statement: 'Hate has no home in San Diego. Islamophobia has no home in San Diego.
'An attack on any one of our communities — on any San Diegan because of who they are, what they believe, or how they pray — is an attack on all of us.'
San Diego Unified Supt. Fabi Bagula added that 'hate has no place in our community or schools' and that 'every student family and community member deserves to feel safe, valued and able to worship and gather without fear.'