The Orange County District Attorney claims he's seen no evidence that police had intentionally tried to kill a homeless man who died after being beaten by six officers from the Fullerton Police Department.
Kelly Thomas, 37, died after resisting arrest in the college town of Fullerton in Orange County.
Video of the incident shows police officers beating and tasering Mr Thomas repeatedly as he lies on the floor crying out for his father.
Eye witnesses said he was unable to offer any resistance as he was beaten beyond recognition by the officers who were responding to reports of a break-in.
But Orange County District Attorney Tony Rackauckas said he'd seen no evidence to suggest Thomas had been intentionally killed.
He told the Los Angeles Times: 'As far as intentional killing — whether an officer intended to kill him ... I have not seen any evidence of that in this case.'
Rackauckas is trying to establish whether excessive force was used during the incident on July 5 this year.
The coroner's office is waiting for results of toxicology tests before they can determine the cause of death. Rackauckas, in an interview with radio hosts John and Ken on Monday said that process could take anywhere from two to six months.
Thomas was left in a critical condition having suffered severe head and neck injuries in the attack.
He was taken off life support and died five days after the incident.
His death has sparked outrage in the city of Fullerton.
According to reports Thomas - who suffered from schizophrenia - caught the attention of the police after someone reported a burglar was breaking into cars parked near a Fullerton bus station.
When officers approached him in the depot parking lot and tried to arrest him, he resisted.
Eye witnesses Mark Turgeon, said: 'They kept beating him and tasering him. I could hear zapping, and he wasn't even moving.
'He had one arm in front of him like this, he wasn't resisting. And they kept telling him, "He's resisting, quit resisting", and he wasn't resisting.'
Members of the Fullerton community described Thomas as a passive, peaceful person.
He had a previous conviction for assault with a deadly weapon 16 years ago which had been attributed to the onset of his mental illness.
Since his death, his family and members of the community have held protests outside the police department headquarters, looking for answers.
His father Ron Thomas, a former sheriff's deputy, claims he rejected a compensation offer of almost $1million, and plans to sue the city of Fullerton.
He said: 'His death was gang-involved, the way I see it. A gang of rogue officers who brutally beat my son to death.'
By Daniel Miller
Mr. Miller is a writer for the Daily Mail