SAN DIEGO — Lilliana Vazquez and Marco Vazquez filed a lawsuit against Park Mental Health Treatment of San Diego on August 31, 2026. The complaint alleges negligence, dependent adult neglect, wrongful death, and medical malpractice following the actions of their son, Caleb Vazquez.

The plaintiffs allege that Park Mental Health Treatment failed to act on warnings regarding Vazquez's dangerous behavior and mental health status. Vazquez was receiving treatment at the facility for autism, OCD, body dysmorphia, social anxiety, severe depression, and psychotic episodes.

Why It Matters

The lawsuit centers on allegations that a mental health provider did not intervene despite specific warnings from federal authorities and family members. The case involves claims of medical malpractice and wrongful death tied to a mass casualty event that resulted in multiple fatalities and the deaths of the perpetrators.

The timeline indicates that law enforcement and family members attempted to communicate risks to the treatment facility in the days leading up to the violence. The outcome involves protocols for handling threats identified through online monitoring and the responsibilities of care providers when patients exhibit signs of radicalization and severe mental distress.

Timeline

Lilliana Vazquez shared the FBI's warnings with Vazquez's therapist on May 15, 2026. She also shared the warnings with a program director at Park Mental Health Treatment on the night of May 15, 2026. Surveillance footage showed Vazquez leaving Park Mental Health Treatment at 8:24 p.m. on May 17, 2026.

On May 18, 2026, Vazquez, 18, and Cain Clark, 17, shot and killed three people at the Islamic Center of San Diego. Both died by suicide after the shooting, according to police reports. Park Mental Health Treatment employees contacted Lilliana Vazquez on the morning of May 18, 2026, to report that Vazquez was missing.

What's New

Later reporting confirmed that on May 18, 2026, Vazquez, 18, and Clark, 17, shot and killed three people at the Islamic Center of San Diego.

Additional details indicate that Vazquez was receiving treatment at Park Mental Health Treatment for autism, OCD, body dysmorphia, social anxiety, severe depression, and psychotic episodes. They released a manifesto before the shooting that contained hateful imagery and messages campaigning for a race war. The pair wore a Black Sun symbol, which is associated with Nazi Germany. The lawsuit alleges negligence, dependent adult neglect, wrongful death, and medical malpractice.

How Sources Differ

Sources differ on the details of the Islamic Center shooting. That on May 18, 2026, Vazquez, 18, and Clark, 17, shot and killed three people at the Islamic Center of San Diego, adding that Vazquez died by suicide after Clark shot him. The San Diego Police Department incident report stated that Vazquez, 18, and Clark, 17, killed three people at the Islamic Center of San Diego on May 18, 2026.

Reports vary regarding Vazquez's death. That Vazquez died by suicide after Clark shot him. The San Diego Police Department incident report said that Vazquez and Clark died by suicide after the shooting.

Sources present different information on Vazquez's radicalization. AP News focused on the shooting event. The San Diego Police Department investigation summary stated that Vazquez and Clark met online and were radicalized in internet circles encouraging Nazi and incel rhetoric.

Details about a manifesto differ between sources. AP News did not mention a manifesto in its primary account. The California Post obtained document reported that Vazquez and Clark released a manifesto before the shooting that contained hateful imagery and messages campaigning for a race war.

Accounts of symbols worn by the attackers vary. AP News did not detail attire in its primary report. The San Diego Police Department evidence log stated that Vazquez and Clark wore a Black Sun symbol, which is associated with Nazi Germany.

Sources differ on attack planning details. The San Diego Police Department incident report noted the killing of three people. The California Post obtained document reported that the pair released a manifesto containing messages campaigning for a race war.

Reports on attack attire differ. The San Diego Police Department incident report did not describe clothing. The San Diego Police Department evidence log stated that the attackers wore a Black Sun symbol associated with Nazi Germany.