Dr Michael Baden points to the location on his head where one of the gunshots struck Michael Brown
The unarmed black teenager killed by a police officer in Ferguson, Missouri, on 9 August was shot at least six times, including twice in the head, a medical examiner has said.
Dr Michael Baden was hired to perform a second, independent autopsy by the family of Michael Brown, 18.
The family have called for the arrest of the officer who killed Mr Brown.
Mr Brown's death has sparked days of unrest and clashes between protesters and police in the St Louis suburb.
Family lawyer Crump said autopsy results corroborated the witness accounts
The officer who shot Mr Brown, Darren Wilson, has been suspended with pay since the shooting, and Mr Brown's family have called for his arrest and prosecution.
As the unrest, marked by a crackdown by riot police wielding tear gas and rubber bullets, has continued, on Sunday Missouri Governor Jay Nixon ordered the National Guard to the town to "help restore peace and order".
On Monday, lawyer Ben Crump said Mr Brown's family had asked Dr Baden to perform an autopsy as they "did not want to be left having to rely on the autopsy done by the St Louis law enforcement... the same individuals they feel are responsible for executing their song in broad daylight".
Shawn Parcells, a forensic pathologist who assisted Dr Baden, said a wound to Mr Brown's right arm may have been sustained as he had his hands up, "but we don't know".
He said the wound was consistent either with having his back to the officer or facing the officer with his hands above his head or in a defensive position. Witnesses have said Mr Brown was shot as he held his hands up in a position of surrender.
Dr Baden, a veteran of the New York City medical examiner's office and nationally prominent forensic pathologist, said his preliminary findings could answer the family's basic questions, including how many times he was shot and if he suffered.
Michael Brown's killing has exposed racial tensions in the majority-black suburb of St Louis
Residents cleaned up debris after another night of unrest in Ferguson
Police fired tear gas on protesters on Sunday evening
"We can answer those questions on day one on the basis of the injuries," Dr Baden told reporters. "Telling that to a family can be very helpful at a trying time."
"The family has a right to know how their loved one died. This calms family or community concerns."
He and Mr Parcells said they believed at least two bullets left re-entry wounds.
One bullet entered the top of his head and another entered directly above his right eyebrow. Mr Brown was 6ft 4in (1.9m) tall.
"All of the gunshot wounds could have been survivable, except the one at the top of the head," Dr Baden said.
Both men said more information was needed, including x-rays from the initial autopsy, the medical evaluation of Mr Wilson and an examination of the clothes Mr Brown was wearing at his time of death.
Dr Baden said there were no signs of a struggle, as abrasions around the teenager's face were likely from falling to the pavement after being shot.
He also believed Mr Wilson did not shoot him at close range as there was no gunpowder residue on his body, suggesting the officer was at least 2ft away.
Another autopsy on Mr Brown by the US justice department, in addition to examinations by Dr Baden's and St Louis county officials.
Timeline of events
Michael Brown had recently graduated from high school.