Judge Elliot Daum said there was no evidence that Alfred Fournier was suffering from a mental illness on July 13, 2004 when he passed motorcyclist Rick Stern then abruptly applied the brakes of his Ford Explorer on a winding rural west Sonoma County road.
Stern died when his motorcycle collided with the rear of Fournier's car.
Daum said Fournier's decision to pass Stern after Stern passed the Explorer was made in anger and was "mystifying."
"The taking of a life in a road rage situation is highly intolerable to the community," Daum said.
Defense attorney Joe Stogner said Fournier suffers from bipolar disorder and asked for probation or a county jail sentence.
He said that since treatment for the illness began several months ago, Fournier now understands the nature and consequences of his action. He said Fournier committed a wrongful and criminal act but did not intend to cause an accident.
Deputy District Attorney Anne Masterson argued there is no substantiation that Fournier suffered from mental illness at the time of the collision and that Fournier's statements afterward show he is "blaming the victim." She said Fournier had anger management treatment before the incident.
"He acted in anger. Rick Stern was killed in anger," Masterson said.
A jury convicted Fournier in July of vehicular manslaughter with gross negligence and assault with a deadly weapon causing great bodily injury. Daum sentenced him to five years in prison on the assault charge and stayed execution of a four-year term for the vehicular manslaughter.
Fournier and his family were driving in two cars to an outing in Armstrong Woods State Park on the day of the collision.
Stern, 55 of Monte Rio, passed Fournier on Bohemian Highway and Fournier then passed Stern and stopped his Explorer on the road after a blind curve, according to trial testimony.
The prosecution argued at the trial that Fournier was angry because Stern passed him and wanted to "teach Stern a lesson."
Stern collided with the rear of the Explorer and died on the side of the road. Masterson said Fournier stood on the side of the road as his sister Kathleen Hart held Stern's head in her hands and prayed with him as he was dying.
Cara Stern, Stern's niece, and Linda Kennebeck, a friend of Stern's family, asked Daum to reject probation and send Fournier to prison. Both said Fournier showed no remorse for Stern's death.
Stern, known in the Russian River area as "Sunglass Rick" because he was usually seen wearing sunglasses, was planning to move to Oregon to be with his family just before he died.
"I am deeply sorry for the wrong that I've done and take full responsibility for my actions," Fournier told the court and Stern's family members.
Stogner said that with 496 days' credit for time already served, Fournier will spend about two years in prison.