---
born: 2008
category: Extremism & Violent Networks
created: 2026-05-21
location: Clairemont, San Diego, California
summary: Cain Lee Clark was a San Diego teenager who co-perpetrated the May 2026 attack
  on the Islamic Center of San Diego, co-authoring an accelerationist manifesto citing
  Siege, Atomwaffen Division, and Terrorgram, and dying at the scene.
tags:
- Person
- SiegeCulture
- Accelerationism
- AtomwaffenDivision
- Terrorgram
- NeoNazi
- AntiMuslim
- Shooter
- SanDiego
- California
updated: 2026-05-21
---

[Cain Lee Clark](/people/cain-clark/) was a 17-year-old resident of the Clairemont neighborhood of San Diego, California who, on May 18, 2026, co-perpetrated the [attack on the Islamic Center of San Diego](/events/2026-islamic-center-of-san-diego-shooting/) alongside [Caleb Liam Vazquez](/people/caleb-vazquez/). Three people were killed in the attack. Clark subsequently shot Vazquez twice in the head inside their vehicle at Vazquez's request, then killed himself. He co-authored a 75-page manifesto titled "The New Crusade: Sons of Tarrant" that cited [James Mason](/people/james-mason/)'s *Siege*, [Atomwaffen Division](/organizations/atomwaffen-division/), [Terrorgram](/organizations/terrorgram-collective/), and [The Base](/organizations/the-base/) and described himself as a "Christian ecofascist."

### Background

Clark grew up in Clairemont, attended Kate Sessions Elementary School, and later the San Diego School of Creative and Performing Arts. He was a member of the wrestling team at Madison High School in the 2024-2025 school year and was on track to graduate in June 2026. From 2021 onward he was schooled partially online. No significant prior disciplinary record was reported beyond a single elementary school incident in 2015. His social media was described by investigators as reflecting "possible associations with nihilistic violent extremist ideology," though no prior law enforcement contact with Clark was on record.

Clark met [Caleb Vazquez](/people/caleb-vazquez/) online before the two discovered they both lived in the [San Diego](/places/san-diego/) area and began meeting in person. The radicalization environment he and Vazquez shared was described by experts as consistent with accelerationist white supremacist online networks that require intentional seeking out, though initial exposure can happen on mainstream platforms.[^1]

### Manifesto Content

Clark contributed a section to the 75-page manifesto "The New Crusade: Sons of Tarrant," which the two co-authored. Clark's section described himself as a "Christian ecofascist." Both sections together cited [Brenton Tarrant](/people/brenton-tarrant/) (the 2019 Christchurch shooter) as an inspiration - the manifesto title explicitly frames the attack as continuing Tarrant's "momentum" - and cited [James Mason](/people/james-mason/)'s *Siege* and William Luther Pierce's *The Turner Diaries* as texts that "should be read almost biblically by all soldiers of the white race."

The manifesto stated the attack was carried out for Atomwaffen Division, Terrorgram, and The Base. It drew extensively on [Great Replacement Theory](/concepts/great-replacement-theory/), framing the attack as a response to Muslim "invasion" of the United States, and expressed systematic antisemitism, with Jews described as "the universal enemy." Physical evidence found on the shooters' equipment included an Atomwaffen Division logo and Sonnenrad patch, linking the attack's aesthetics to the visual grammar developed by AWD and distributed through Terrorgram channels.

Clark also left a suicide note that was separately leaked; it contained explicit writing about "racial pride."[^2][^3]

### The Attack and Aftermath

Clark and Vazquez attacked the Islamic Center of San Diego on the morning of May 18, 2026, shooting three victims outside the mosque before security guard Amin Abdullah engaged them in a gun battle that delayed their advance and allowed approximately 150 students in the attached school to shelter safely. The two fled and drove away; during the escape they fired on a landscaper, whose bullet was deflected by his helmet. They were found dead approximately three-tenths of a mile from the mosque. Vazquez had asked Clark to kill him; Clark shot Vazquez twice in the head and then killed himself. No criminal prosecution is possible given both perpetrators' deaths.

[^1]: NBC News. "San Diego mosque suspects' writings reveal influence of online extremism." May 2026. https://www.nbcnews.com/tech/internet/san-diego-mosque-shooting-extremism-online-accelerationist-livestream-rcna346066
[^2]: ADL. "San Diego Mosque Shooters' Apparent Manifestos Reveal Anti-Muslim Extremism." May 2026. https://www.adl.org/resources/article/san-diego-mosque-shooters-apparent-manifestos-reveal-anti-muslim-extremism
[^3]: Daily Beast. "Leak Reveals Mosque Gunman Cain Clark's Disturbing Racial Pride Suicide Note." May 2026. https://www.thedailybeast.com/leak-reveals-mosque-gunman-cain-clarks-disturbing-racial-pride-suicide-note/