A private forensic pathologist who performed an autopsy on Michael Brown will testify before the grand jury deciding whether to charge the Ferguson police officer who shot him, the attorney for Brown's parents said Wednesday.

Attorney Benjamin Crump confirmed that former New York City Chief Medical Examiner Dr. Michael Baden is scheduled to testify Thursday. Ed Magee, a spokesman for St. Louis County prosecutor Bob McCulloch, declined comment. Messages seeking comment were left with Baden.

Crump said Brown's parents are pleased that Baden will testify, but skeptical about the objectivity of the process.

"Their reaction was that they want the jury to hear from an independent witness not associated or controlled by the police department," Crump said. "They feel that all the local authorities are going to work together to try to exonerate the killer of their child."

Brown's parents are in Geneva, where the U.N. Committee Against Torture is hearing testimony this week about U.S. policies.

Brown was shot in the St. Louis suburb of Ferguson on Aug. 9 after Officer Darren Wilson, who is white, ordered Brown, who was black, and a friend to stop walking in the street.

The shooting of the unarmed 18-year-old led to sometimes-violent protests and the St. Louis region is bracing for renewed unrest once the grand jury decision is announced. Activists want Wilson charged with murder, but the grand jury could choose manslaughter or no charges at all.

Tension has been fueled by leaks suggesting the grand jury, which has been meeting since Aug. 20, has already made a decision. McCulloch on Monday called the leaks "rank speculation" and said the grand jury was still hearing evidence. A decision is expected this month.

Fordham Law School professor Jim Cohen questioned why Baden is being called so late in the proceedings.

"That makes me concerned about the whole presentation to the grand jury," Cohen said. "If they (prosecutors) didn't present this medical examiner's testimony and report, it does suggest it was not a balanced presentation."

Baden performed his autopsy in August at the request of Brown's family. His findings and the findings of the St. Louis County Medical Examiner's office seemed to differ on one key point: Baden said there was no gunpowder residue on Brown's body, indicating he was not shot at close range, though he said at the time he wasn't given access to Brown's clothing and the residue could be there.

The county autopsy report showed that one wound, to Brown's thumb, was at close range. Wilson told investigators he felt threatened while fighting with Brown from inside a police SUV, where an initial gunshot was fired, according to information provided to several news outlets by people described as familiar with the investigation, but not otherwise identified.

Those same accounts said Wilson told investigators that after Brown fled the vehicle, he turned around in a threatening manner, prompting Wilson to fire the fatal shots. But some witnesses said Brown had his hands up as if he was trying to surrender.

The Justice Department, which is investigating both the case and the Ferguson police department, performed a third autopsy. Those results have not been released.

Crump said Baden had only limited access to information and has asked to review several other pieces of evidence before he testifies.