>> i didn't do it. >> unlike rex, thomas is a complete stranger to the criminal justice system. >> here, he's 12. his sister's dead. he's emotionally an infant at this point. emotional wounds were visible, this child would have bled to death before the first interview was over. >> in the summer of 2006, thomas is about to enter the eighth grade. while living here with kaylee and their mother, melody jones. melody is on disability, she tells authorities she suffers from mental illness. and has attempted suicide at least once. >> she could go from one emotion to the other in a snap.