The fact that he has family in both states will be helpful, but I would look into the rules of establishing residency for the particular state that he is considering. I am not sure if having an address is enough. I don't know - and therefore am suggesting caution - rather than get into some ramble with the IRS over state taxes. The examples I gave were legal ways of establishing residency that you and I are familiar with, and have experience with, through the military.

USMCFLYR