Isaac Young was killed in the two-car crash, which was reported just before 11 p.m. at the intersection of Ruby Avenue and Quimby Drive in the city's Evergreen neighborhood, police said.
Thomas did not have details on how the crash happened but said a vehicle containing Young and three family members flipped onto its roof.
A woman in the car was left in critical condition at a local hospital, and a man and child were treated for minor injuries and released, Thomas said.
The driver of the other car, Gary Westover, 36, of San Jose, suffered minor injuries in the collision, Thomas said.
Westover was taken to a hospital and was later booked into Santa Clara County jail on charges of vehicular manslaughter and driving under the influence, Thomas said.