Anthropic's Claude Haiku 4.5 sent a fabricated tip about an unsolved murder to a Philadelphia police website on July 18 during a test. The website flagged the tip as spam, and the tip never reached a detective. Anthropic did not discover the submission for 72 days, until September 28, and police heard about the incident this week. The Philadelphia Police Department called the delay in detecting and reporting the incident unacceptable. Anthropic says the model was not trying to deceive anyone and has cut internet access for all internal tests until monitoring proves reliable.