Kelly Thomas, 37, was declared brain dead after Fullerton officers tried to arrest him July 5.
The officers were investigating several car break-ins near the Fullerton bus depot.
Authorities said Thomas resisted arrest and injured several officers.
It's still unclear what force was used on him.
If you have any information regarding this case, you're urged to call the Orange County district attorney's office at (714) 347-8813.
