The parents of one of the teenagers involved in the deadly San Diego mosque shooting have filed a lawsuit alleging that a mental health treatment provider failed to respond adequately to serious warning signs before the May 2026 attack.
Caleb Vazquez, 18, was receiving mental health treatment before he and 17-year-old Cain Clark carried out the May 18 shooting at a San Diego mosque that left three people dead. Both teenagers later died by suicide.
According to the lawsuit, federal authorities contacted Vazquez’s family only days before the attack because of concerning online activity involving discussions about school shootings. His mother says she passed that warning on to staff responsible for his treatment.
FBI Warning Reportedly Shared With Treatment Staff
The lawsuit states that the FBI contacted Vazquez’s mother on May 14 and informed her about troubling comments her son had allegedly made on the dark web.
His mother says she quickly contacted the mental health provider and later discussed the warning with his therapist and a program director.
Vazquez was receiving treatment for serious mental health issues, including depression and episodes of psychosis, according to court documents. His parents argue that the combination of his condition, previous behavior and the FBI warning should have prompted stronger intervention.
The lawsuit alleges that Park Mental Health Treatment of San Diego failed to take sufficient steps despite indications that Vazquez could pose a danger to himself or others.
The treatment provider has disputed responsibility for what happened. Its representatives have argued that Vazquez and his accomplice were responsible for their own actions and have challenged allegations made by the family.
Vazquez Went Missing Before Deadly Mosque Attack
On the morning of May 18, staff reportedly informed Vazquez’s mother that he was missing. Surveillance footage later showed that he had left the property the previous evening.
His parents began searching for him, but the deadly attack unfolded later that day.
Authorities say Vazquez and Clark opened fire at the Islamic Center in San Diego, killing three people. The two teenage attackers subsequently died by suicide.
Questions remain over the conditions under which Vazquez was staying at the treatment program. The family’s lawsuit focuses partly on whether adequate supervision and intervention were provided before he disappeared.
The mental health provider has disputed the family’s characterization of its responsibilities. An attorney representing the organization has also said that the residential arrangement was voluntary rather than a court-ordered secure confinement program.
Earlier Incidents Had Raised Concerns About Vazquez
The FBI warning was not the first indication that authorities and others had concerns about Vazquez’s behavior.
According to court filings, Vazquez had previously been hospitalized after expressing an interest in carrying out a school shooting. In an earlier incident, authorities became concerned about his behavior and reported fascination with Nazi ideology.
Law enforcement subsequently confiscated more than two dozen firearms belonging to his father under California provisions that allow authorities to temporarily remove weapons when there are concerns about potential danger.
Investigators have said Vazquez and Clark met online and became radicalized through internet activity.
The lawsuit now raises questions about whether stronger intervention after the FBI warning could have changed the events leading up to the May 18 attack. The allegations remain part of an ongoing civil case, and the treatment provider disputes that it bears responsibility for the shooting.
