Two police officers are dead and two people wounded after a man went on a shooting spree in California.

The violence - which was stretched over several bloody hours and at least two counties - began around 10.30am on Friday when a police deputy went to investigate a suspicious vehicle parked at a hotel in Sacramento.

As he approached, the driver opened fire and struck the deputy in the forehead, Sacramento Sheriff Scott Jones told a news conference.

The deputy, Danny Oliver, a 15-year veteran who was married with two daughters, was killed.

The shooter and a woman accomplice who was also in the car sped away from the scene.

A short time later, they carjacked a vehicle and when the driver resisted, he too was shot in the head, Jones said. His condition was not immediately known.

The duo then carjacked another vehicle, this time a red pickup truck, without injuring the driver, and sped into neighbouring Placer County.

Somewhere along the way, two more police officers were shot. One of them was killed, authorities told local media.

A police spokeswoman in Placer County, Dena Erwin, said a suspect had been tracked down and taken into custody.

Local media identified him as Marcelo Marquez and said he was arrested by police in a home and carried away on a stretcher.

He was thought to be alive, but it was unclear whether he was suffering any injuries.

The woman suspect was arrested earlier.