The report rules out positional asphyxia as the cause of death and shows 41-year-old Raymond Johnson had a significantly enlarged heart.
A witness used a cellphone to record the incident last Friday near a Burger King. Authorities were responding to reports of a man sitting inside a vehicle, violently kicking his feet and striking his fists in an uncontrollable manner.
When officers arrived, police say Johnson was agitated and refused to get out of his vehicle, even after officers used pepper spray and a Taser. Officers believed the man was under the influence of alcohol, narcotics or both, and due to his physical size, additional officers were requested. Johnson was 6 feet 2 inches tall and weighed 216 pounds.
Video shows officers pulling him out, then beating him with what appears to be a baton. Authorities said the baton was used to loosen Johnson's grip on the under carriage of the passenger seat so he could be removed from the vehicle. But the baton was ineffective, police said, so an officer kicked Johnson in his shoulder area.
Eventually, Johnson was removed from the vehicle, handcuffed and placed on the ground. As he was laying on the ground, police noticed that he had stopped breathing. Officers gave him chest compressions, but he died at the hospital.
The autopsy noted that the abrasions on Johnson's body were consistent with being involved in a struggle with police, but the injuries were not life-threatening. A toxicology report is pending.
Meantime, the District Attorney's Office is looking into whether the officers did anything illegal.
"If there is not criminal liability, then they'll be cleared of any potential criminal charges in this case," said John Hall with the Riverside County District Attorney's Office.
Authorities are asking that anyone who witnessed the confrontation to call Investigator Campos of the Riverside Sheriff's Central Homicide Unit at (951) 955-2777 or Investigator Lenton of the Moreno Valley Police Department at (951) 486-6700.