The classic note passer. The career criminal who while always very dangerous, is also the most likely to study and understand your preventative program. He will analyze his options and develop a plan to assure the highest probability of meeting his objectives which are to obtain as much money as possible, in the shortest period of time while not hurting anyone, unless it becomes necessary, and then making a successful escape. And because of his method, he as with the intermediate robber can be deterred to a high degree by your preventative efforts. Quite simply, he may look before he attacks and if he does not like what he sees, he will quickly seek another target.
Professionals are usually loners as they know friendships can eventually cause problems.
He is most likely to case your bank prior to the attack. He has self-confidence and may even come in, introduce himself, and then sit and talk with you. He is more prone to attempt a robbery by extortion or hostage taking. When he commits his crime, he may be successful as he will be in control and likely counter your security measures, if you allow him to do so. He prides himself on the competency of his work, and he has discipline.