We are a private association library. There is a "difficult" patron who sits on a bench (almost everyday doing nothing but trying to talk to anyone nearby) which is immediately next to our front doors on library property. We are doing curbside pick-up so the staff places the library items immediately outside the front doors on a table. The patrons come to the table to pick them up. The "difficult" patron refuses to wear a mask no matter who asks and how many times he is asked. We recently found out that he was exposed to someone who has COVID. The police tried to offer a mask to this patron and he still refused. We were told to call the police if he returns. When he did, the police never came. This patron is a health hazard to the staff and our patrons. What else can we do?