"While we cannot comment on personnel matters, I can confirm that Manuel Ramos is no longer employed by the City of Fullerton," Fullerton Police spokesman, Sgt. Jeff Stuart, said.
It was unclear if Ramos was fired or had resigned.
Thomas was severely injured in a confrontation with a group of Fullerton police officers on July 5, 2011. He died days later from his injuries.
Ramos was charged with second-degree murder and involuntary manslaughter, while Cpl. Jay Cicinelli faces involuntary manslaughter charges in the beating. The arraignment for the two officers has already been postponed several times to give the defense more time to work on a motion to dismiss charges. They are scheduled to appear in court for an arraignment hearing on July 17.