The term for what you want in your state is "annulment" and you have to wait three years and it's still not going to be hidden from view by other law enforcement background checks. As pointed out, being of bad moral character is a pretty big strike against you for getting such job. About the only thing worst is being a liar. Answer truthfully any questions about your history on the application because being determined to be a liar is going to be about the worst thing that can happen. Nobody wants a cop they can't trust to tell the truth in the various statements and testimonies.