Stewart said detectives won't see the medical examiner's report until it's finished.
Oklahoma County District Attorney David Prater, whose office would be responsible for prosecuting the case, said the report should be withheld until it's complete, saying the Open Records Act gives investigating agencies leeway in when such reports can be made public.
â€œI completely agree with Dr. Sibley's decision not to release any information from the autopsy report until a final report is issued,â€ Prater said.
What's in the report?
Few significant developments in the Mitchell case have been made public lately, but the contents of the medical examiner's file might include facts that could shed light on what happened.
The report will include a diagram of the body, which in turn will show where Mitchell's injuries were and how many injuries she had, Ballard said.
Also in the report will be a physician's report, which could include more detailed descriptions of her injuries or any toxicology findings, such as substances that may have been in the victim's bloodstream. Other facts could include the address of the victim, her age or the cause of death.
Many of those details, though, can be sensitive to the investigation, Stewart said.
Precise information about how a person was killed could be things that only investigators and the killer or killers would know, he said. By keeping that information secret, it helps detectives separate bad information from clues that could help solve the case.
Legal advice sought
Pressure to release the report â€” and to withhold it â€” prompted the medical examiner's office to seek the state attorney general's opinion on what to do, Ballard said.
Part of the reason goes back to another high-profile case that occurred last year.
On Aug. 23, 2009, Carol Daniels, pastor at Anadarko's Christ Holy Sanctified Church, was killed inside the church building.
The Oklahoma State Bureau of Investigation had sought to keep the medical examiner's report secret, citing the same concerns expressed by Oklahoma City investigators now.
But the initial autopsy report was released through an Open Records request, revealing the pastor's hair had been set on fire and her head nearly cut off. Daniels' mutilated and nude body was found in what appeared to be a â€œcrucifix positionâ€ behind the altar of the church.
The case remains unsolved.
Ballard said the medical examiner's office sought legal advice on the Mitchell case because of fears that a similar disclosure could hamper Oklahoma City detectives' efforts.
Ballard would not say what the attorney general's office told them.
Charlie Price, spokesman for Attorney General Drew Edmondson, said he couldn't discuss the details of that request.
â€œWe gave them our legal opinion, and we did that as their lawyers,â€ Price said. â€œSo we think this falls under attorney-client privilege, so we can't discuss that unless they waive their attorney-client rights.â€