Child molester Gary Walker (inset) has languished behind bars for nearly one third his 71 years, tormented by his desire for sex with young boys. The septuagenarian has never had a sexual relationship with an adult. He has confounded keepers. Despite undergoing a battery of treatment programs to root out his sexual deviance, experts say he grapples still with “intrusive sexual thoughts” and remains a “significant risk” to molest more young boys if he is released.