By Carey Gillam

(Reuters) - The official autopsy on an unarmed black teenager whose killing by a white police officer set off months of protests in Ferguson, Missouri, suggests he sustained a gunshot wound to the hand from close range, the St. Louis Post-Dispatch reported.

The autopsy report, obtained by the newspaper and published on its website late on Tuesday, comes as a St. Louis County grand jury considers charges against Ferguson Police Officer Darren Wilson in the Aug. 9 shooting of 18-year-old Michael Brown.

Accounts of the shooting differ, but witnesses and law enforcement officials have said Brown and Wilson got into an altercation through the window of the officer's vehicle after Wilson told Brown and a friend to leave the middle of a street.

Brown, who was shot six times, died about 30 feet from the patrol car.

At least one of the shots struck Brown's hand at close range, according to the autopsy, which forensic experts interviewed by the Post-Dispatch said indicated that Brown's hand was close to Wilson's weapon at some point.

A representative for the St. Louis County medical examiner verified the autopsy report but said the office did not release it.

Some activists said the leak of the report appeared to be part of an orchestrated effort to bolster support for Wilson and had added to tensions in the strained community.

"It is intentional that they are leaking this stuff," said Tory Russell, an organizer of Hands Up United, which has called for Wilson to be charged for shooting Brown. "At every turn they are saying Mike Brown was a bad guy and deserved to die."

Brown's death has sparked protests across Ferguson, a primarily black community with a mostly white police force and city government, and has drawn global attention to race relations in the United States.

Protesters have said they expect widespread unrest if Wilson is not charged, and local and state authorities have said they are preparing for that possibility.

Story continues

The Post-Dispatch report came days after the New York Times, citing federal government officials briefed on a separate civil rights investigation, reported that Wilson told investigators he feared for his life and battled with Brown in his vehicle over his gun.

The autopsy said a microscopic examination of Brown's hand tissue showed particles "consistent with products that are discharged from the barrel of a firearm." But the autopsy noted there was no "powder stipple," or residue often left by guns fired at close range.

Brown also tested positive for marijuana, the medical examiner found.

Benjamin Crump, an attorney for Brown's parents, said the autopsy was not surprising given that several witnesses said there was an altercation at the patrol car.

"What we want to know is why Officer Wilson shot Michael Brown multiple times and killed him even though he was more than 20 feet away from his patrol car; this is the crux of the matter," Crump said in a statement.

(Reporting by Curtis Skinner in San Francisco and Carey Gillam in Kansas City, Mo.; Editing by Bill Trott and Peter Cooney)