MILLBRAE — An investigation into online threats and the firing of a gun inside a Millbrae apartment ended Thursday in the arrest of a 27-year-old man, authorities said.
On Wednesday, deputies learned the suspect was sending messages that raised concerns about violence toward others or potential self-harm, according to the San Mateo County Sheriff’s Office. He allegedly admitted in one of the messages to firing a gun inside his home and included a photo of a bullet hole in an interior wall.
The man had previous contacts with law enforcement and had multiple firearms registered in his name, authorities said.
Deputies obtained arrest and search warrants and a gun violence restraining order for the suspect.
On Thursday, deputies arranged to meet the man outside his apartment building in the 100 block of North Rollins Road and safely took him into custody, authorities said.
Inside the suspect’s apartment, deputies found several firearms and an assault rifle “with characteristics classifying it as an illegal weapon,” according to the sheriff’s office. Deputies also seized a cache of ammunition, tactical gear, including a bulletproof vest, and pills that appeared to contain fentanyl.
“Sheriff’s deputies also located recently patched holes in the walls of the apartment, consistent with the bullet holes seen in online messages,” authorities said.
The man was booked into San Mateo County jail on charges of discharging a firearm with gross negligence and possessing a controlled substance with a firearm.