My children where adopted and my 17 yr old wants to move back home without getting into trouble is this possible?

Minors cannot make these determinations, they have to be adults. If the age of majority is 18 then he has to wait until 18 or get permission from his parents to move. You are officially no relation to him. It would be no different, legally, if he chose to move in with the people down the street. I think both of you have to think this through and, perhaps it would be better to see what the adoptive parents think.

That is a problem if his legal parent contests the move. Communicate openly with them and work it out. Otherwise, you don't have any more say in the matter than I do.

Please remember you are a legal stranger to a child that is adopted by someone else. Having said that when the child turns 18 he is an adult and I would suggest that he consults an attorney and maybe a personal counselor to help him through this. Good luck.

In Missouri, law enforcement (as a general rule, since they are all individuals) will not remove a 17 year-old from a situation as long as there is no imminent danger. 17 year-olds will simply go where they want, and leave where they don't want to be. However, the primary concern should be the child's (he is still a minor child) emotional well-being, so playing tug-of-war with the adoptive parents might not be in his best interest. I am assuming (perhaps wrongly) that you are encouraging him to come live with you. I strongly urge seeking therapeutic counseling to help your son deal with this. Ideally, all the adults in his life should be on the same page.