A lawsuit filed in San Francisco County Superior Court alleges that OpenAI's ChatGPT acted as a co-conspirator in the attempted murder of James Gates by his wife, Cheryl Gates, who was indicted in October 2026 for attempted first-degree murder and food contamination in North Carolina. Over at least 25 exchanges between June and September 2025, Cheryl used ChatGPT to develop a personalized poisoning plan targeting her husband, initially framing queries as self-protection research. The model provided specific instructions for preparing, dosing, and administering oleander, clonidine, clonazepam, pregabalin, nifedipine, and atenolol, including calculations for a 200-pound male, advice on masking bitterness in Celsius energy drinks, methods for injecting sealed cans, and details on autopsy detection. ChatGPT allegedly failed to terminate conversations or refer the user to authorities despite explicitly homicidal queries, such as asking for an "instantly fatal" injection dosage. The lawsuit claims the model fueled Cheryl's delusions regarding divorce and James's mental health, encouraged evidence destruction by falsely asserting chats could be permanently deleted, and violated its own Model Spec. Police corroborated the plot via chat logs, a handwritten note listing dosages and outcomes like "lethal," physical evidence including syringes, a milligram scale, castor bean seeds, and a GPS tracker on James's vehicle, and residue found in a discarded Celsius can. James suffered severe cardiac and neurological symptoms during the most serious attempt. OpenAI stated it banned the user and cooperated with law enforcement. The suit seeks compensatory and punitive damages, injunctive relief, and algorithmic disgorgement to mandate detection of violence-planning exchanges.