The parents of a California teenager who shot three people to death at a mosque with the help of an accomplice have sued the mental health facility where he was being treated.

Caleb Vazquez, 18, and Cain Clark, 17, committed the horrific shooting at the Islamic Center of San Diego on May 18, killing a security guard and two community members.

The teenagers were found dead inside a car by authorities after the killings. Clark had shot Vazquez in the head before killing himself.

According to a lawsuit filed in San Diego County Superior Court on Monday by Vazquez's parents, Lilliana and Marco Vazquez, their son had a history of serious mental illness. 

The parents have accused Park Mental Health Treatment of San Diego, the facility where Vazquez was being treated, of causing his death through negligence and medical malpractice, according to a civil complaint reviewed by the Daily Mail.

The lawsuit states that Vazquez was taken to a hospital in January 2025 after a classmate reported that the teen said he wanted to commit a school shooting. Vazquez had also allegedly expressed [self-death] ideation on social media. 

Vazquez was discharged from the hospital after three days, but was later admitted to Park Mental Health in April after he was diagnosed with autism, OCD, body dysmorphia, social anxiety and severe depression with psychotic episodes, according to the lawsuit.

On May 14, four days before the mosque shooting, the teenager's mother was notified by the FBI that Vazquez had been talking to people on the dark web about school shootings and [self-death], the lawsuit said. 

The mom, Lilliana, immediately reached out to Park Mental Health and her son's therapist, Mikayla Weathers, but did not hear back until the next morning, according to the lawsuit.

The therapist, who was also named as a defendant in the civil complaint, set up a conversation with the mother on May 15 and said she had been contacted by the FBI as well, the lawsuit said. 

Three days later, on the morning of the shooting, Weathers texted Vazquez's mother asking, 'Do you have any idea where Caleb could be?' according to the lawsuit. 

'Are you saying that he's missing?' Lilliana replied before Weathers wrote back, 'Yes,' the lawsuit said. 

Vazquez's parents immediately hopped in their car and drove to the Park Mental Health housing where their son had been living, the lawsuit said. 

They then allegedly spoke with the house manager, who showed them a surveillance video of Vazquez pacing back and forth the prior evening while on the phone with someone before leaving at 8.24pm, according to the lawsuit. 

The parents drove around for hours looking for their son but could not find him. 

They then went to see his therapist, but she would not meet with them, and when Lilliana asked why no one had told her Vazquez had gone missing the night before, 'no one responded,' the lawsuit said. 

They drove home shortly before noon. Later that day, they would learn the horrific news that Vazquez and Clark had fatally shot three people before Clark also shot his accomplice then turned the gun on himself. 

The lawsuit alleges that Park Mental Health and the other defendants engaged in 'negligent failure to take steps to protect... Vazquez from his own self destructive actions in a timely manner,' especially after having just been contacted by the FBI.

It also claims that the defendants failed in their standards of care by failing to put Vazquez in a 'locked and secure facility... and otherwise prevent him from escaping their custodial care,' after learning of his online conduct. 

The civil complaint alleged four causes of action including negligence, dependent adult abuse or neglect, wrongful death and medical malpractice. 

Vazquez's parents are seeking punitive and other damages in an amount to be determined through court proceedings. 

Chris Saldana, an attorney for Park Mental Health, told NBC San Diego that his client engaged in no wrongdoing and denied the lawsuit's allegations. 

'Caleb was at a house not represented as a secure facility. There was no court ordered confinement,' the lawyer told the outlet. 

'The lawsuit makes many incorrect factual assertions,' Saldana added. 

Park Mental Health has not yet filed a formal response to the lawsuit. It has a month to do so. 

The Daily Mail has reached out to Park Mental Health for further comment. 

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