It's times like this when you feel let down by the system and nowhere to turn to. Pity no-one has suggested any CCTV in the locality?
I have been in similar situations where the Police can't or won't intervene but as soon as you seek retribution you are the guilty party, a no-win situation I'm afraid. However if threatening behaviour was reported then that must be followed up.
VOSA would have been high up on my list if that were me. This is when people need voice recorders