REDWOOD CITY -- A South San Francisco man pleaded not guilty Friday to accusations that he killed his cousin in a drunken-driving accident Dec. 18, prosecutors said.

Dennis Rogelio Salguero, 22, was charged with vehicular manslaughter and drunken driving after the accident that killed 33-year-old Gilbert Vallejo, of Daly City, and injured another passenger, San Mateo County District Attorney Steve Wagstaffe said.

According to Wagstaffe, Salguero spent the afternoon drinking tequila shots at his father's Daly City home, where his father and uncle later told him to take BART home. Salguero then "insisted" he take his car home, Wagstaffe said, and embarked with his two cousins back to South San Francisco.

Witnesses later told authorities that Salguero was "speeding and swerving" across northbound Interstate 280 before he lost control of his car, Wagstaffe said. The vehicle veered across every lane before it crashed into the center divider.

Vallejo was ejected from the back seat of the car and pronounced dead at the scene, authorities said. The second cousin, who was sitting in the front seat, was taken to the hospital with moderate injuries.

Salguero was found unconscious in the driver's seat and was later arrested, Wagstaffe said. Two blood samples taken from Salguero revealed he had a blood-alcohol content of 0.14 and 0.13 two hours after the crash.

Salguero will return to court Jan. 8 for a preliminary hearing, Wagstaffe said. He remains in jail in lieu of $250,000 bail.

Contact Erin Ivie at eivie@bayareanewsgroup.com. Follow her at Twitter.com/erin_ivie.