A pathologist hired by attorneys for the family of an unarmed man killed by Sacramento, California, police says an independent autopsy shows Stephon Clark was shot seven times from behind and took up to 10 minutes to die.

Dr. Bennet Omalu told a news conference Friday that Clark was shot in the right back side of the neck and had a cluster of wounds in the upper right side of his back.

The pathologist says any one of those wounds would have been fatal, and death would have taken three to 10 minutes.

Police have said Clark was facing and advancing toward officers who thought he had a gun when they fired, and then could not approach Clark for five minutes.

The pathologist says Clark also suffered an eighth gunshot wound to the thigh that occurred as he was falling or already on the ground.