A Catholic Church/parish in my city puts on an annual sweet corn festival in the month of August. Two years in a row, something similar (with the same demographic group) happened. Instead of closing the festival down, they enclosed the entire area with 6ft high chain link fence, had one entrance, charged admission, and had city police and county sheriff patrolling the area. If trouble started, the problem people were swarmed, arrested, and removed from the area. Those measures eliminated the problem. And the festival returned to being a fun event.