I just dealt with an almost identical transaction the other day (sibling in prison included) and the property had a bunch of tax liens on it making it worthless once the liens were paid off.

This is what a quick google search revealed:  In Michigan, possession must be actual, visible, open, notorious, exclusive, hostile, continuous, and uninterrupted for the statutory period of 15 years.The laws in VA where I live are written the same way.