An FBI keyword alert to Argentine prosecutors in August led to a September 11 raid on a 15-year-old in Quilmes who had queried ChatGPT for school attack logistics; tactical gear was seized but no weapons were found, and the case marks the first documented instance of AI chatbot monitoring producing a cross-border law enforcement search.

Two civilians died and three Minneapolis officers were wounded after a gunman opened fire in a downtown apartment tower on September 2; the shooter, evicted from the building that afternoon, died of a self-inflicted gunshot wound.

Washington Park on Chicago's South Side was the scene of a mass shooting late August 30 that left one dead and 14 wounded, the largest mass casualty shooting in Chicago this year, with no suspects identified by the following morning.

A North Carolina grand jury on August 31 indicted 17-year-old Sarah Santiago on three murder counts for allegedly agreeing to publish the San Diego mosque shooters' manifesto and distribute their livestream, extending criminal liability for mass shooting facilitation beyond the physical participants for the first time in a US mosque attack case.

A Sand Springs, Oklahoma marijuana extraction facility exploded on August 27, killing two people and damaging 25 businesses, and Ryan Bassham was charged with two counts of first-degree murder as state and federal investigators pursued the case.

Multiple people including children died Sunday night after a domestic disturbance at 315 White Star Circle in Billings, Montana turned into a combined shooting and house fire, with the suspect dying of a self-inflicted gunshot wound and fire crews unable to reach victims during the active shooter standoff.