Police identify UPS gunman as SF man

View from Vermont at 17th streets a block from the mass shooting incident inside the UPS facility on San Bruno took place between 16 and 17th streets where four are dead (including shooter) with one more victim status unknown on Wednesday, June 14, 2017, in San Francisco, Calif. less View from Vermont at 17th streets a block from the mass shooting incident inside the UPS facility on San Bruno took place between 16 and 17th streets where four are dead (including shooter) with one more victim ... more Photo: Liz Hafalia, The Chronicle Buy photo Photo: Liz Hafalia, The Chronicle Image 1 of / 53 Caption Close Police identify UPS gunman as SF man 1 / 53 Back to Gallery

San Francisco police were digging into the past of a United Parcel Service employee as they tried to figure out why he allegedly killed three co-workers at a company distribution center before shooting himself to death Wednesday.

The San Francisco Police Department identified the shooter as Jimmy Lam, 38, of San Francisco. They seized Lam’s BMW, which was parked near the shooting scene, and raided his home in San Francisco’s Inner Richmond neighborhood, where neighbors said he mostly kept to himself.

Workers at the UPS building at 320 San Bruno Ave. said the gunman was a fellow employee, and Assistant Police Chief Toney Chaplin said the shooter was wearing a UPS uniform.

A union official said Lam had filed a grievance complaining that he was working excessive overtime, according to the Associated Press.

Lam’s neighbors said they often saw him walking around in a company uniform, looking at his phone and smoking a cigarette.

In the afternoon, officers left his home — one of two units in a grayish-green building — with what appeared to be a computer, several bags of evidence and a file box. Around the same time, police towed away a black 2012 BMW coupe registered to Lam that had been parked near the shooting scene.

“I’m a little creeped out,” said Jennifer Plog, who lives next door to Lam’s home and said he had appeared harmless. “It’s creepy knowing that people next door have the ability to have guns and shoot people they work with. It makes me feel unsafe.”

No one interviewed in the neighborhood of two-story homes and apartments said they had spoken with Lam.

According to court records, Lam’s only brushes with the law involved driving. In 2010, he was convicted of driving under the influence and was placed on probation after San Francisco police said he crashed into parked vehicles. He allegedly had neither a valid license nor insurance.

Three years later, city prosecutors filed a motion to revoke his probation when he was arrested again for driving under the influence.

Police officials said they recovered two guns from the scene of the shooting, including what they described as an assault pistol. They did not provide further details or say where the guns had come from or whether they had been legally purchased.

The shooting happened at 8:55 a.m. as UPS workers gathered for a regular meeting called Wednesday Wellness, causing panic as employees dived to the ground or ran for safety. In addition to killing three, the gunman wounded at least two others, while three people were injured while fleeing, officials said.

When responding police officers encountered the suspect inside the building, officials said, he raised a pistol to his head and pulled the trigger.

Vivian Ho and Michael Cabanatuan are San Francisco Chronicle reporters. Email: vho@sfchronicle, mcabanatuan@sfchronicle.com. Twitter: @VivianHo @ctuan