If one of the other “passengers” claims to know something they would be stupid not to follow that up too to try to get more clues, but there are motive questions there as well. And why wouldn’t the “passenger” say to someone “that guy you had back here before you chucked us in? he was throwing himself around like a mad man on speed, you ought to check him out.”
Yeah there are motive questions, but would a man being transported in a meat wagon give information helpful to police? Seems like they would do the exact opposite, so I am not sure what to think of all that at this time.
But I would say that GPS data would show what it shows without any sort of bias one way or the other, and the autopsy report should do the same.
I would think that if the injuries are the result of a beating with hands and feet or batons, that would be obvious to a coroner.
I will be very interested to see this report.