scotgirl,
from the stories about kids who were put into this type of ring, they were brainwashed to believe their families would not want them back, they are "tarnished", or they would kill their families if they ever said anything. Many of the kids get hooked on drugs supplied by their pimps and die of overdoses. I have no clue if he is alive or not. There are signs that Johnny Gosch is alive. Jeff Guckert never took a DNA test to prove he wasn't Johnny.
If they want to know if that guy is Johnny, get his DNA off of a glass or something like that. It would be no problem at all. None.