Did You know that You cannot take discipinary action against a non-employee. It is neither wise to take disciplinary action against an employee for something they did before you employed them.
But what do you do if you can not continue to employ someone in whom you have lost all trust and confidence. If you haven't lost all trust and confidence in them, then that's another thing.
Best approach always is to have an honest conversation with them, in which you explain what you have discovered and get their explanation. Unless it completely exonerates them, explain the ri