Joseph Andrew Farnsworth, 21, of El Cerrito did not speak during the sentencing hearing, which filled a courtroom with family members and supporters of the 25-year-old victim, William Maclean of San Leandro.
Maclean was shot during a road rage incident in which a burrito was thrown at the vehicle carrying Farnsworth.
"I do not understand such rage and anger that would cause the taking of a life," said Maclean's grandmother, who declined to give her name. "I don't understand."
Farnsworth's sentence was determined in advance under a plea bargain with the district attorney's office.
The plea arrangement precluded Judge Kelly Simmons from adding more prison time, despite pleas from family members to do so.
"I appreciate that you have suffered a great loss that will always be in your heart," Simmons told the gallery. "Sadly, I can't fix that."
Farnsworth received nearly 600 days of credit against his prison sentence for time already served since his arrest, plus good conduct in jail.
As with previous hearings, the courtroom and outer hallway were lined with sheriff's deputies and investigators for extra security, but the 15-minute hearing passed without incident.
Many of Maclean's supporters wore Hells Angels jackets from various chapters in California, or T-shirts with the victim's picture. Maclean, described as a Laney College student with an interest in accounting and real estate, was not a member of the motorcycle organization, but he had family and social ties to the group.
"Twenty-one years for killing someone?" Karen Dewaal of Oakland, a close friend of Maclean's, said after the hearing.
The shooting occurred May 24, 2008, on northbound Highway 101 in Mill Valley, where a red Dodge Durango and a white pickup truck were jockeying during a road rage dispute.
Farnsworth, a passenger in the Durango, fired a gun at the pickup truck, killing Maclean in the front passenger's seat. The pickup's driver, Maclean's brother-in-law Raymond Foakes, was not hit by gunfire.
After the Durango escaped and police arrived, it transpired that Maclean was riding in the lead vehicle of a Hells Angels convoy heading north on Highway 101 after a member's funeral south of San Francisco.
Sheriff's investigators were able to identify the red Durango and track down its driver, Jessica Andrea Gordon, a 22-year-old Mill Valley resident. After contacting Gordon, investigators identified the passengers in the Durango as Farnsworth and his juvenile girlfriend.
Farnsworth was charged with murder and Gordon was charged with being an accessory, drug possession and other counts. The girlfriend, a Richmond resident, was not charged.
Gordon was eventually granted immunity in exchange for her cooperation against Farnsworth.
Read more Mill Valley stories at the IJ's Mill Valley section.
Contact Gary Klien via e-mail at firstname.lastname@example.org