The sheriff isn't saying the behavior is legal, it's just that they can't afford to post a deputy on every corner. If you follow the advice above and give them some suspects you might have some luck... or you might show up one day to find the shop burnt to the ground.
It seems your dad's neighborhood is sliding down the slope. It could be a long time before it climbs back up. I'd move.
I am a Soldier. I fight where I'm told, and I win where I fight."
GEN George S. Patton, Jr.