An unarmed black teenager had marijuana in his system when he was fatally shot six times by a white police officer, two people familiar with the official county autopsy of Michael Brown said Monday.

The autopsy by St. Louis County chief medical examiner Mary Case, released to state prosecutors late Friday, found that Brown, 18, had six gunshot wounds to the head and chest and was shot from the front, the people said. They spoke on condition of anonymity due to the sensitivity of Brown’s death, which has triggered violent protests in this St. Louis suburb that continued Sunday night.

In a brief interview with The Washington Post, Case declined to comment on specifics of her examination of Brown’s body but said she welcomes the two other autopsies being performed. One was done Sunday by forensic pathologists Michael Baden and Shawn Parcells, and Case said the second — ordered on Sunday by Attorney General Eric H. Holder Jr. — will be done by Pentagon medical examiners.

“I welcome anyone who wants to do additional autopsies,’’ Case said. “Michael is someone I know and think highly of, and I think highly of the Armed Forces also. I’m not upset at all. This is highly controversial case, and it’s good that everyone interested in it can have a say.”

Benjamin Crump, an attorney for Brown’s family, said Case’s results “sound consistent” with Baden’s highly publicized autopsy, but Crump said he was unaware of any marijuana in Brown’s system. Baden also concluded that Brown was shot at least six times, according to a preliminary report on an autopsy he and Parcells performed Sunday at a funeral home in Ferguson.

The multiple and competing autopsies point up the highly unusual nature of the investigation of the death of Brown, who was killed Aug. 9 by Ferguson police officer Darren Wilson. It will be up to local prosecutors, along with Justice Department officials conducting a separate civil rights probe of the shooting, to sift through the various findings and determine whether criminal charges will be filed. Federal investigators will take into account Case’s autopsy, along with the federal one, Justice officials have said.

Case’s finding of marijuana in Brown’s system is potentially sensitive but also had been anticipated by the protesters who have flocked into the streets of this community of 21,000 in recent days. Expecting that Brown would be potentially vilified by the results of a drug test, conducted as a routine part of the autopsy, protesters have insisted that Wilson should be required to submit one as well. It is unclear whether that has happened; authorities have released virtually no details about Wilson or his whereabouts.

“What was in the system of that cop when he was pumping bullets into that boy’s body?” asked a protest leader, shouting into a megaphone, during a rally on Friday afternoon.

Brown’s family requested Baden’s independent autopsy because “they did not want to rely on the same institution that executed their son in full daylight. They could not trust what would be put in the reports about the tragic execution of their child,” Crump said at a news conference Monday announcing Baden’s results.

Baden, a medical examiner who was featured in the HBO show “Autopsy,’’ has consulted on investigations relating to the deaths of civil rights leader Medgar Evers and actor John Belushi.

During the news conference at Greater St. Marks Family Church in Ferguson, Baden said his preliminary autopsy revealed there were no signs of struggle between Brown and the officer and that all of Brown’s gunshot wounds were survivable except one from a bullet that entered at the top of Brown’s head and went downward through his brain.

Baden said there was no gunshot residue on Brown’s skin, which would determine how far away the shots were fired.

But Baden emphasized that he did not have enough information to make a final determination about what exactly happened in the confrontation.

“We need to look at the clothing. . . . We need to look at x-rays,” Baden said. “They should be available at some time, depending on what the prosecutors’ wishes are. . . . At some point, the decedent’s family should have access to the clothing. . . . The clothing is now in the St. Louis County police agency. It is up to them when the family will have access.”

“There are many witness accounts,” Baden said. “We need more forensic evidence. From a science point of view, we can’t determine which witnesses’ statements are consistent with the findings.”

Surrounded by the family’s lawyers, the medical examiner stood in the church pulpit, next to an anatomical diagram of the body, which showed six wounds.

The family autopsy found that Brown was shot once in the top of his head at the apex. One wound was on his right elbow, with another on his right arm. There was also a graze wound in the middle of his right arm, and a wound to his right hand.

Daryl D. Parks, another lawyer representing the family, said the results supported the contention of Brown’s family that he was killed as he was trying to surrender and that Wilson should face charges.

“The killer shot hit Mr. Brown at the apex of his head,’’ Parks said. “There was a second round near his hairline, which went in and came out. This supports what witnesses said: He tried to surrender. Why would he be shot in the top of his head? Those two things are ample evidence for this officer to be arrested.”

Markon reported from Washington. Adam Goldman and Wesley Lowery in Washington contributed to this report.