A preliminary autopsy report by the Hennepin County Medical Examiner found "no physical findings that support a diagnosis of traumatic asphyxia or strangulation," according to the criminal complaint released by the Hennepin County Attorney's Office.
The preliminary results are a combo of the restraint, his underlying physical condition and potential intoxicants in his system caused his death.
At this point you have no idea what or how much of anything he had in his system or which of the three causative elements was the predominate factor, yet you want to charge murder. You can’t just arrest, you need to charge. It’s stupid to do that when you have time to line up all of yer ducks or at least get a final cause of death.