David Sal Silva, 33, died last week after the beating in East Bakersfield, the Los Angeles Times reported. In a controversial move, deputies took two witnesses into custody, releasing them after they surrendered their cellphone cameras.
Kern County Sheriff Donny Youngblood said Monday the cameras were seized to preserve evidence. He said police in Bakersfield, the county seat, have been asked to analyze the footage.
One witness, a woman, called 911.
"The guy was laying on the floor and eight sheriffs ran up and started beating him up with sticks," she said. "The man is dead laying right here, right now. I got it all on video camera and I'm sending it to the news. These cops have no reason to do this to this man."
Another man, Ruben Ceballos, 19, told the Times the sound of batons striking woke him up.
"He was screaming in pain ... asking for help," Ceballos said Monday. "He was incapable of fighting back -- he was outnumbered, on the ground. They just beat him up."
David Cohn, a lawyer for Silva's four children and his parents, said he has not seen the video footage from the scene. He said seizing the cameras has a look of "cover up."