I seem to recall police in a few other cases pumping lots of bullets into cars and persons on just suspicion;i find that troubling.
Not saying Perry was a good guy.
The investigation will give some answers, but I would bet:
Cops trailing someone for 30 minutes had a reason to do so.
Cops trailing someone for 30 minutes would call in the tag for information if they did not already know who they were following.
In either case they would know who he was and that he had a record and convictions for violence against cops.
Cops do not trail people for no reason.