It will help if you have a written lease as that clearly states the terms of the rental. If you gave him the 30 days notice on Mar 16th, then he can stay up to April 15th, if he pays the rent for April. The rent for March is applied to the 30 days of that month. If he does not want to pay rent for April and wants to move out on April 1st, it will be better to just let him go. He's a lawyer and knows that you'll have to go through the process of eviction, so you can get him out of your home. This is a lengthy process and you'll need to hire a lawyer to represent you, so it's not worth your time and trouble, if the two of you can not get along.