ATF arrests two new suspects connected to Orinda mass shooting

Two more people have been arrested by federal agents in connection with the investigation into a shooting at a Halloween party in Orinda that killed five people and wounded nine more.

The federal Bureau of Alcohol, Tobacco Firearms and Explosives arrested two people Thursday on warrants obtained by the Contra Costa County Sheriff’s Office, ATF spokesperson Alexandria Corneiro said.

While executing the warrants, ATF agents seized a gun that was linked through ballistics testing to multiple other shootings in the Bay Area, Corneiro said.

The arrests follow previous arrests of five suspects who were released after the Contra Costa County District Attorney’s Office declined to charge them with crimes.

According to the sheriff’s office, prosecutors wanted more investigation before bringing criminal charges.

The sheriff’s office has been investigating the Oct. 31 shooting with the assistance of federal agents. Gunfire broke out in a 4,000-square-foot home at 114 Lucille Way shortly before 11 p.m. during a large Halloween party.

The home had been booked for the party on Airbnb. Police said when they arrived, more than 100 people were trying to flee the premises.

Three people were already dead. Two others died after they were taken to a hospital. Three more were taken to a hospital with injuries.

Police said after the shooting that they were unsure how many people might have been injured and taken themselves to a hospital. ATF officials said Thursday that a total of nine people had been wounded in addition to the five who died.

Sheriff’s officials made arrests of five people on Nov. 14. But on Monday, the district attorney’s office announced that it had declined to file charges against any of them.

The ATF also announced a $20,000 reward for information leading to arrests in the case. Anyone with information has been asked to call (888) ATF-TIPS.