The autopsy showed that Brown, who was 18 and unarmed, had been shot at least six times by police officer Darren Wilson, including two shots in the head, attorney Benjamin Crump said.
Another attorney, Darryl Parks, elaborated on the two shots to the head. One shot appeared to enter Brown's forehead and exit near his eye, which suggests that Brown's head was in a downward position, he said.
That suggested that Brown had been "trying to surrender to the officer," Parks said, noting that Brown was six-feet, four-inches tall. The so-called killshot had entered Brown at the apex of his head, he added.
"We believe that given those types of facts, it shows this officer should have been arrested," Parks said.
Michael Baden, a former New York City medical examiner who conducted the family's autopsy, said that it was difficult to tell what order the shots were fired in, but he said he believed the shots to the head were fired last.
He also said that there was "no gunshot residue" on Brown's skin, though he had not been able to examine Brown's clothing, and that there was no evidence of a physical struggle.
"The muzzle of the gun was at least one to two feet away," Baden said, adding that it "could have been thirty feet away."
Baden is expected to consult soon with the St. Louis County medical examiner who performed the official autopsy. The Justice Department has also ordered its own examination.