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.
EVERY time a bad cop gets away with committing a crime under color of authority it sends EXACTLY the wrong message to all sides of the issue.
Cops trail people for many reasons;most of the time the reason is legitimate.Sometimes it is just to fill a stupid ticket quota.
GOOD cops and citizens should not fear holding police to a high standard.With the power SHOULD come great responsibility to use that power wisely.
Actually we ought to hold our public officials to such high standards.