FULLERTON (CBS) — Fullerton police are under fire after the violent death of a schizophrenic homeless man.

Six police officers are suspected of beating Kelly Thomas, 37, to death and the police department is being accused of withholding video evidence.

READ MORE: Pursuit Suspect Attacks CHP Officers In Simi Valley

Orange County District Attorney Tony Rackauckas spoke exclusively to CBS2/KCAL9 about the investigation.

Rackauckas said security video taken by the Fullerton bus depot is not enough to zero in on any aspect of this case.

“I can tell you that there is no evidence whatsoever that there’s any intention of killing this person,” Rackauckas said of the footage. “But it does show a good deal of force and a lot of struggle — so, that’s where the issue lies.”

Rackauckas won’t allow that video to be shown publicly until the investigation is over, likely when the autopsy is final.

Orange County’s Chief Deputy Coroner Jacque Berndt said that most cases take 2-6 months, sometimes even a year.

Thomas showed significant bruising on his face in photos taken of him in the hospital.

READ MORE: Funeral Service Held In Covina Hills For Lance Cpl. Dylan Merola, Among The 13 Killed In Aug. 26 Bombing Attack In Kabul

“It is not prudent to assume or jump to any kind of conclusion before you really have the opportunity to look at it,” Berndt said.

Authorities conducted a preliminary autopsy; the results were inconclusive and more testing was deemed necessary.

Every toxicological exam has been ordered and 25 D.A. investigators have been assigned to the case.

Fullerton City Manager Joe Felz announced Monday he will ask the City Council to hire a firm of independent investigators, operated by Michael Gennaco, to look into Thomas’s death. Gennaco runs the OIR Group and is the chief attorney for the Los Angeles County Office of Independent Review, a civilian oversight committee founded by county supervisors to monitor the L.A. County Sheriff’s Department.

“There will be a result here, sooner rather than later. It will be an honest result.  We’ll either bring charges and, if we don’t bring charges, there’ll be a detailed explanation as to why not,” Rackauckas said.

Meanwhile, the six Fullerton police officers involved in this case remain on paid leave.

MORE NEWS: Acura Grand Prix Of Long Beach Returned This Weekend After Pandemic Forced Cancellation Of Last Year's Events

»RELATED: Former Fullerton Police Chief Sympathizes With Family Of Schizophrenic Man
»RELATED: Witnesses Recount Alleged Fatal Beating Of Homeless Man By Officers