Juan Nunez, 43, was identified by Hayward police as the man who caused the crash that killed 40-year-old Dennis Splan on Saturday night.
Splan, of Hayward, was a passenger in a Toyota Tundra that was traveling south on Hesperian Boulevard when it was rear-ended by a speeding black Toyota Land Cruiser at about 7:45 p.m. Saturday, police said.
The impact caused the driver of the Tundra to lose control and strike the center median, according to police.
Splan was taken to Eden Medical Center where he later succumbed to his injuries. The driver of the Tundra suffered minor injuries, police said.
The driver of the Land Cruiser, later identified as Nunez, suffered minor injuries in the crash. He was taken to Kaiser Permanente's Oakland Medical Center where he was later arrested.
Police are seeking vehicular manslaughter and felony DUI charges against Nunez, as well as two counts of hit-and-run, according to county inmate records kept by the sheriff's office.
Shortly before the fatal crash, Nunez was allegedly involved in two hit-and-run collisions near Hesperian Boulevard and Tennyson Road, police said.
Nunez was scheduled to be arraigned today at the Hayward Hall of Justice, according to the inmate records.