https://www.mercurynews.com/2019/11/21/atf-gun-in-orinda-shooting-linked-to-others-new-reward-offered/

As the Bureau of Alcohol, Tobacco, Firearms and Explosives announced a $20,000 reward for information leading to an arrest in last month’s fatal Orinda Airbnb shooting, it said agents recovered a firearm during enforcement actions Thursday.

The lethal shooting happened at an Oct. 31 party advertised on social media as a mansion party in a short-term rental residence and left five dead and four others injured, forcing dozens of attendees to hide or run screaming.