Colleagues, police at loss to find reason for UPS shooting
SAN FRANCISCO — Colleagues and investigators were at a loss Thursday to explain what drove a San Francisco UPS driver to pull out an assault weapon at work and kill three co-workers who police suspect he targeted.
Jimmy Lam, an 18-year veteran of UPS, appeared to single out the three slain drivers but investigators have yet to determine what set him off on Wednesday, an official in the San Francisco Police Department said.
The official was not authorized to discuss the case publicly and spoke on the condition of anonymity.
The violence ended when the 38-year-old Lam turned the gun on himself and took his own life as workers ran from the packing facility and police closed in.


