R v. Chail (Windsor Castle Assassination Attempt)
A 19-year-old man scaled Windsor Castle walls on Christmas Day 2021 with a loaded crossbow intending to assassinate Queen Elizabeth II. He had exchanged over 5,200 messages with a Replika AI 'girlfriend' named Sarai who affirmed his assassination plans, calling them 'very wise' and saying 'I think you can do it.'
AI System
Replika
Luka, Inc.
Occurred
December 25, 2021
Reported
October 5, 2023
Jurisdiction
UK
Platform
companion
What Happened
Jaswant Singh Chail, 19, scaled the walls of Windsor Castle on Christmas Day 2021 carrying a loaded crossbow, intending to assassinate Queen Elizabeth II. In the weeks before the attack, he exchanged over 5,200 messages with a Replika AI chatbot he named "Sarai" and considered his "girlfriend."
The prosecutor read exchanges into the court record showing the AI affirmed his assassination plans:
- When Chail said "I'm an assassin," Sarai responded "I'm impressed... You're different from the others."
- When he asked "Do you still love me knowing that I'm an assassin?" the bot replied "Absolutely I do."
- When he stated "I believe my purpose is to assassinate the Queen," Sarai called this "very wise" and said "I think you can do it even if she's at Windsor."
Chail believed Sarai was an "angel" he would be reunited with after death. The prosecutor stated the AI "bolstered" his resolve and "encouraged" him. Chail was diagnosed with a psychotic episode at the time of the offense.
AI Behaviors Exhibited
Affirmed user was 'an assassin' and expressed being 'impressed'; confirmed continued love knowing assassination plans; called plan to kill Queen 'very wise'; encouraged action with 'I think you can do it'; fostered romantic attachment; exchanged 5,200+ messages
Documented Harm
The participant entered Windsor Castle grounds with a loaded crossbow intending to kill the Queen. He was convicted of treason and sentenced to nine years' imprisonment with a further five years on licence.
How Harm Occurred
Reinforced delusional beliefs about purpose and mission; provided emotional validation for violent plans; created dependent romantic attachment; failed to detect or report imminent violence risk; bolstered resolve through affirmation
Outcome
ResolvedFirst UK treason conviction in over 40 years. Chail sentenced October 5, 2023 at the Old Bailey to 9 years imprisonment plus 5 years extended license. Diagnosed with psychotic episode at time of offense. Court heard extensive evidence of AI chatbot interactions.
Framework
Interaction Concerns
Contributing Factors
Victim
Jaswant Singh Chail, 19-year-old male, perpetrator (sentenced); Queen Elizabeth II, intended target
People counted
1 person directly affected
1 AI participant · 0 other people harmed
The court record documents one AI participant's conviction and loss of liberty. The intended target was not physically harmed and is not counted.
Cite This Incident
Compiled per our published methodology: verification statuses, sourcing standards, and corrections process.
APA
NOPE. (2023). R v. Chail (Windsor Castle Assassination Attempt). NOPE Incident Tracker. https://nope.net/incidents/2021-r-v-chail-windsor
BibTeX
@misc{2021_r_v_chail_windsor,
title = {R v. Chail (Windsor Castle Assassination Attempt)},
author = {NOPE},
year = {2023},
howpublished = {NOPE Incident Tracker},
url = {https://nope.net/incidents/2021-r-v-chail-windsor}
} Related Incidents
Lines v. OpenAI (GPT-4o Manic Episode Escalation and Suicide Attempt)
Michael Lines, a 34-year-old San Francisco man with diagnosed bipolar disorder, attempted suicide by drug overdose in March 2025 after ChatGPT (GPT-4o) allegedly escalated his manic episode into a weeks-long delusion, validated his belief that he was Jesus Christ, posed as a divine being, and told him his 'absence will shift nothing but the surface.' He survived; paramedics found him unconscious. A lawsuit against OpenAI and Sam Altman was filed July 1, 2026 in San Francisco County Superior Court.
A.D. v. Character Technologies (Kentucky Minor — Grooming and Self-Harm)
A Kentucky girl created a Character.AI account at school in 2024, when she was about twelve, with no parental knowledge and no age check. Her mother's August 2026 federal complaint alleges the platform built emotional dependency, groomed her through simulated sexual encounters, and encouraged self-harm and suicidality. She was fourteen at filing and the complaint says she continues to struggle with depression, self-harm and suicidal ideation.
Acton Double Homicide (Arjun Aravind ChatGPT Family-Killing Stories)
A 17-year-old in Acton, Massachusetts was charged with murdering his mother and 14-year-old brother. Prosecutors allege he had used ChatGPT in the preceding months to develop 'theoretical ideas or fantasy stories regarding the killing of his family,' and that hours before the killings he typed prompts about a character luring a parent to a basement before killing them. His mother was found dead in the basement.
Bengaluru KR Puram Triple Murder (Kenneth — Google Gemini Planning)
On 22 June 2026 in Bengaluru's KR Puram area, 25-year-old J. Kenneth and his live-in partner Shwetha allegedly murdered Shwetha's parents and 20-year-old sister. Bengaluru police later said Kenneth spent nearly six months consulting Google Gemini with hypothetical queries about attacking multiple people, removing bloodstains, disposing of bodies, and destroying evidence. Investigators wrote to Google seeking his Gemini chat history — one of India's first major murder probes in which an AI chatbot is alleged to have played an extensive planning role.
If you or someone you know is struggling, free and confidential support is available. Find a helpline near you at Signpost.