Last Updated Aug 18, 2014 6:21 PM EDT
FERGUSON, Mo. - An unarmed 18-year-old whose fatal shooting by police has sparked a week of protests in suburban St. Louis suffered a bullet wound to his right arm that may indicate his hands were up or his back was turned, a pathologist hired by his family said Monday.
But the pathologist said the team that examined Michael Brown can't be sure yet exactly how the wounds were inflicted, citing the need for more information.
The incomplete nature of the private autopsy done for the Brown family means it likely won't be considered by prosecutors, CBS News correspondent Bob Orr reports.
The St. Louis County medical examiner's autopsy found that Brown was shot six to eight times in the head and chest, office administrator Suzanne McCune said Monday. But she declined further comment, saying the full findings were not expected for about two weeks.
But there is wide distrust in the community, so the Justice Department is now conducting a third autopsy, which will be compared to the county medical examiner's, as part of its federal civil rights investigation, Orr reports. The federal autopsy will be carried out by one of the military's most experienced medical examiners, Attorney General Eric Holder said.
Holder was scheduled to travel to Ferguson later this week to meet with FBI and other officials carrying out the independent federal investigation into Brown's death. More than 40 FBI agents are on the ground doing interviews and collecting evidence.
The independent autopsy determined that Michael Brown was shot at least six times, including twice in the head, the family's lawyers and hired pathologists said.
Witnesses have said Brown's hands were above his head when he was repeatedly shot by an officer Aug. 9 in Ferguson.
Forensic pathologist Shawn Parcells, who assisted former New York City chief medical examiner Dr. Michael Baden during the private autopsy, said a bullet grazed Brown's right arm. He said the wound indicates Brown may have had his back to the shooter, or he could have been facing the shooter with his hands above his head or in a defensive position across his chest or face.
"We don't know," Parcells said. "We still have to look at the other (elements) of this investigation before we start piecing things together."
In Washington, President Barack Obama said the vast majority of protesters in Ferguson were peaceful, but warned that a small minority was undermining justice.
During a brief pause in his summer vacation, Obama said overcoming the mistrust endemic between many communities and their local police would require Americans to "listen and not just shout."
The president also weighed in for the first time publicly on the militarization of some local police departments, saying it would probably be useful to examine how federal grant dollars had been used to allow local police to purchase military-style equipment.
Missouri Gov. Jay Nixon mobilized the National Guard to help manage the unrest. Mr. Obama said he told Nixon that he wanted to ensure the Guard's mission was limited in scope. CBS News correspondent Vladimir Duthiers reports that there are roughly 80 National Guard troops in Ferguson, mostly military police.
Also Monday, Nixon lifted the neighborhood's midnight-to-5 a.m. curfew two days after it went into effect when he declared a state of emergency. The governor had summoned the National Guard overnight after police again used tear gas to quell protesters.
Brown's death has heightened racial tensions between the predominantly black community and Ferguson's mostly white police department. Another protest quickly deteriorated Sunday night as marchers pushed toward one end of a street, and authorities - who said they were responding to reports of gunfire, looting, vandalism and protesters hurling Molotov cocktails - pushed them back with tear gas.
Nixon said the National Guard troops would be under the direction of the Missouri State Highway Patrol, which is overseeing security during protests. Their primary objective is to protect the police command center.
News of the National Guard deployment brought hope to Ibrahim Ramaha, whose store has been looted twice. When asked what he wanted the National Guard to do, Ramaha said "just bring the city back, give rest to the family, give rest to the business community, give rest to the business owners."
Police were telling protesters Monday that they could not assemble in a single spot, saying they had to keep moving. In federal court, a judge denied a request from the American Civil Liberties Union for a restraining order that would have prevented authorities from enforcing the rule.
Authorities were also establishing a designated protest zone for nightly demonstrations. The plan was announced Monday by St. Louis County police.
It was not clear what would happen to those who refuse to use the area along West Florissant Avenue, where the majority of protests have occurred.
A grand jury could begin hearing evidence Wednesday to determine whether the officer, Darren Wilson, should be charged in Brown's death, said Ed Magee, spokesman for St. Louis County's prosecuting attorney.
Family attorney Benjamin Crump said Brown's parents wanted the additional autopsy because they feared results of the county's examination could be biased. Crump declined to release copies of the report.
"They could not trust what was going to be put in the reports about the tragic execution of their child," he said during Monday's news conference with Parcells and Baden, who has testified in several high-profile cases, including the O.J. Simpson murder trial.
The second autopsy, Crump said, "verifies that the witness accounts were true: that he was shot multiple times."
Baden said one of the bullets entered the top of Brown's skull, suggesting his head was bent forward when he suffered that fatal injury. The hired pathologists said Brown, who also was shot four times in the right arm, could have survived the other bullet wounds.
Baden also said there was no gunpowder residue on Brown's body, indicating he was not shot at close range. However, Baden said he did not have access to Brown's clothing, and that it was possible the residue could be on the clothing.
Crump also noted that Brown had abrasions on his face from where he fell to the ground, but there was "otherwise no evidence of a struggle."