SAN JOSE, Calif.—Police and federal investigators sought on Thursday to determine why a Northern California transit employee opened fire on his co-workers, killing nine people in the latest mass shooting to haunt the United States.
The accused gunman shot himself as police closed in on him, minutes after gunfire erupted at about 6:30 a.m. Pacific time at a light rail yard in the heart of Silicon Valley, according to Santa Clara County Sheriff Laurie Smith.
