The gunman who San Francisco authorities say shot and killed three UPS co-workers before killing himself Wednesday told some of his colleagues to "get out" while targeting others that he apparently felt had belittled him, NBC Bay Area has learned.
A fuller picture is emerging of the chaos that erupted right after a routine morning meeting at the UPS processing facility in San Francisco’s Potrero Hill where four people, including the shooter, died and two others were injured.
After that briefing, about 9 a.m., Jimmy Lam, 38, began firing at co-workers, killing Benson Louie, 50, and Wayne Chan, 56, both of San Francisco, as well as Mike Lefiti, 48, of Hercules. Two other workers were injured — one shot in the arm, the other in the leg.
Authorities say the incident could have been far worse, given the weaponry Lam had and the many rounds of ammunition he had stowed in a backpack.
"There are people he could have shot, but he did not take the shot," one law enforcement source said Thursday.
According to authorities, Lam’s son was taking a test that morning and his wife was out of town.
Lam was apparently going down a flight of stairs in the building when he was met by as many as four tactical officers, headquartered around the corner of the building.
He was holding a Mac-10 assault pistol at the time and appeared to challenge the officers, authorities say.
"He was urging them to come forward — it looks like he was at the end of his rope at that point," one source said.
Other authorities with knowledge of the investigation said the man briefly pointed the Mac-10 machine pistol at the officers and then turned the weapon on himself.
Police officers kicked the weapon out of his hands after Lam fell to the ground.
Officers also recovered a second weapon — a semi-automatic handgun — and a backpack filled with hundreds of rounds of ammunition, authorities say. At least one of the weapons was not registered to Lam, sources told NBC Bay Area.
Police searched Lam’s duplex home on Fourth Avenue in the Inner Richmond on Wednesday, seizing a computer and several bags of evidence.
Neighbors recalled that Lam was regularly seen in his brown uniform, using his cell phone outside his home and smoking out of his upper floor window. They said he kept to himself and did not greet neighbors as they passed by.
Records show Lam's only criminal contacts were related to drunken driving cases in 2010 and 2013.
He had recently filed a grievance over overtime practices at the facility. His complaint was unresolved at the time of the rampage.