I do not know how large your branch network is, but perhaps also offering the teller a lateral transfer to another branch may also be appropriate.
This is excellent advice. I would be very concerned about anyone taking pictures in my branches- particularly pictures of the staff, and particularly a photographer who is 'a little off'.
I also agree with the suggestion to contact the authorities. Perhaps the local police have dealt with this guy and can provide some valuable insight. If necessary (depending on what new insight you gain), close his account and send him a letter letting him know he is unwelcome on any of your premises.
I'm sorry if this sounds like overkill, but I take harassment of branch staff very seriously, and I would not be willing to leave anything to chance in this situation.