Sooner or later you've got to land, whether the cabin's secure or not. There are only so many times you can tell the passengers what to do and if they choose to ignore you then they put themselves at risk. Personally I would probably break off the approach at 1000ft and get delaying vectors or hold until the passenger decided to behave or we approached our reserve fuel levels, at which point the safety of everybody else and the aircraft takes precedence and we land. Then the police come and take the disruptive passenger away in handcuffs.