17-year old Matthew Hicks' arrest came after Vallejo police reviewed surveillance tape of the attack. The victim suffered a fractured skull, jaw, collarbone and broken teeth.
On Tuesday, Hicks pled not guilty to the assault.
Early Monday, his father, 42-year old Matthew Hicks, was fatally shot in the head outside a Vallejo house.
Investigators are looking for two men in that case. So far, they have no motive.
