SAN FRANCISCO (AP) -- -- A union official says the gunman who shot and killed three people at a UPS warehouse in San Francisco had filed a grievance complaining that he was working excessive overtime.
Joseph Cilia, an official with a local Teamsters Union, says Jimmy Lam's grievance filed in March requested that UPS relieve him of working overtime going forward.
Still, Cilia says Lam wasn't angry, and he could not understand why he would open fire on his colleagues at a morning meeting on Wednesday.
Cilia says Lam targeted three fellow UPS drivers. Cilia says two other drivers who were wounded have been released from the hospital and will be OK.
Police say the gunman killed himself after the shooting.
Investigators recovered two firearms from the scene.
Uniformed UPS employees were later led out in a line by officers next to a highway. They walked away calmly with emergency vehicles nearby and gathered nearby outside a restaurant.
It came the same day a gunman opened fire on Republican lawmakers at a congressional baseball practice, wounding U.S. Rep. Steve Scalise of Louisiana and several others.