What would you do which is an ethical question

I would like to pose an ethical dilemma to you. There is not necessarily a "right" or "wrong" answer. I am just curious on your thoughts.

You are a leader of a major law firm in New York, and you are attending a law workshop you have put together, and you are under suspect that one of the lawyers may have cheated on his/her bar exam. What should you do when you are convinced that the situation involves clear ethical code violations, and you are in doubt about how to best deal with the situation? Should you gather all the information you can on that individual or go straight to the CEO and report what you think has been done?