Steven Uselton and his 17-year-old son Douglas were killed.
Police said Angel Lopez from Anaheim was driving west on Crescent Avenue when he hit the Useltons' car.
Lopez, 18, was booked on suspicion of two counts of vehicular manslaughter while intoxicated.
Douglas Uselton was a senior at Oxford Academy. He was a star baseball and basketball player.
Worried teachers from the school called his house when the teen and his father didn't arrive at the speech tournament.
Grief counselors were later made available to Uselton's teammates.
City News Service contributed to this report.