A Northern California police officer died in a motorcycle crash, authorities announced Tuesday. San Jose Police Chief Eddie Garcia said Officer Michael Katherman, 34, was riding his patrol motorcycle in uniform when he was involved in a head-on collision with a minivan at around 4:30 p.m. Garcia said at a news conference that the driver attempted to make a left turn down a street when he collided with Katherman on his motorcycle. A witness pulled over to assist Katherman and used his police radio to call for help. The officer was transported to Regional Medical Center where he was later pronounced dead.