Weird Traffic in Milton???

I was visiting family last week in Milton was getting some weird P25 transmissions 151.415 (NAC 300). From what I can tell it belongs to the Milton FD. However, I was getting half encrypted traffic over it. Sounded like dispatch was encrypted, and a police officer talking about setting something up at the old mill by the tracks. It seemed weird to get half encrypted law enforcement traffic over the FD frequency about something at the mill, any ideas whats going on?