Seth Cravens, 22, is accused of murder in the beating death of a professional surfer Emery Kauanui, Jr., 24. Prosecutors allege that Cravens was involved in incidents in which 10 victims were assaulted and threatened.
On Monday, prosecution witness Chris Jarrett told the court that Cravens was part of a violent group that started a bloody fight at Windansea Beach in La Jolla in August 2006.
"I was, you know, freaking out because there were eight or nine guys, you know, trying to beat me up ... a couple of them were like, 'You ready to die? You ready to get served?' " Jarrett testified.
The prosecution could rest its case on Tuesday after testimony from the medical examiner and a doctor.
Cravens could face 15 years to life in prison if convicted.