The family says surveillance video shows that Jonathan Cuevas posed no threat during the 2010 incident.
Video shows a squad car pulling up next to three men walking along the street. A deputy flashes a light at them.
As he exited the car Cuevas, 20, started running and the deputy shot at him.
"He fires six shots running towards Jonathan, and the seventh shot he stands over Jonathan and shoots him right through the torso, as a coup de grace kill shot," said James Segall-Gutierrez, an attorney for the Cuevas family.
"Was he armed? Yes. Is the whole story being told now? No. Let's not forget who has already investigated this: Internal Affairs, Office of Independent Review monitoring that. Homicide Bureau. The District Attorney," said Sheriff's Spokesman Steve Whitmore.
Segall-Gutierrez says Cuevas' fingerprints were not on the gun the department claims he was carrying, and questions its authenticity.