Eileen is correct. I've been the parent in this situation and when he turned 17, the police department in Missouri told me there was nothing they could do about him moving out.
This is the second post I've seen where people are uneducated about the laws in Missouri giving 17 year olds false information.
As a guardian who has dealt with this I assure you at 17 you can leave and police CANNOT be forced by law to make you come back home. I know this because I had full...