It's extremely scary, especially when you can't watch them 24/7. Very frightening you were threatened with jail and child neglect when you had no idea he was running away or why. Can see how it could up being a game too, the more you play into it. I think urgent professional help is needed. This is a child you are trying to adopt and it won't go well if these things are happening. There could be many reasons, trauma, attachment issues, hyperactivity, missing where he last was, medication etc. Certainly fostered and adopted children experience attachment issues, emotional turmoil and trauma. Although I wasn't fostered, I am adopted. I remember about 3 years old leaving hte house early one morning when my mother was at Church. I wasn't on my own in the house and my father and another sibling was there but asleep, so did they didn't notice me going out. I climbed up on a chair and open the door and walked along the street in my bed clothes. Some neighbours found me and brought me back luckily but it could've been much worse. I think I may have been trying to follow my mother to the church. When I was a child, I had some attachment issues and always looked for my mother. I don't know what to say, but be extremely careful, as you don't want this happening again.