Scott Harlan Thorpe, 40, allegedly walked into the county social services building with a handgun Wednesday and shot three people, two fatally. He then went to a restaurant less than two miles away and killed the manager and wounded a cook, Nevada County Sheriff Keith Royal said.
Thorpe was unhappy with the mental-health care he received at the county clinic and believed the restaurant was poisoning him, his brother, Kent Thorpe, told authorities.
The Sacramento police officer turned Thorpe in after authorities launched a manhunt. He surrendered following two hours of telephone negotiations.
The day's events stunned residents in Nevada City, a town of about 3,000 in a rural area in the Sierra Nevada foothills, about 50 miles north of Sacramento.
"It is a dark day for our county," county board Chairwoman Elizabeth Martin said. "I'm here to express our deep grief and horror at this loss to our community and offer our condolences to the families."
Ted Christensen, a manager at a video store across the street from the restaurant, said he had just arrived at work when he saw several people running out of the building, ducking behind cars in the parking lot and hiding behind shops.
"I've lived in this town for 18 years and I've never heard of anyone going on this kind of shooting spree," said Christensen, who hid behind his car after learning shots had been fired.
The slain victims were Laura Wilcox, 19, who worked in the county building; Pearlie Mae Feldman, a visiting 68-year-old caregiver; and Mike Markle, 24, the restaurant manager.
The sheriff identified the woman wounded at the county building as Judith Edzards, 49, who was hospitalized in critical condition. The restaurant cook, Richard Senuty, 34, was listed in good condition.
A fourth person broke her leg jumping from a county building window to escape, Royal said.
Employees at the social services building were placed on administrative leave and were not expected to return to work until Tuesday.
Martin said officials would discuss whether to add security at the building, which has no metal detectors, guards or surveillance system.
"We prefer not to do business behind bulletproof glass here in Nevada County," she said. "We resolve issues feistily but certainly not violently."