Hi..I wondered about polygraphs..........I wondered if they really know if they are lying.seeing as they don't live in the real world and everything they say has to be scrutinised before you can believe even a half of it. With P here, she does know when she is lying.she isn't  a stupid person even though she did terribly at school. As a young child, she was very bright but with the onset of puberty her mind seem to wander to more destructive  measures. Not surprised really about the case worker......Ps evoke a sense in us that makes us want to reach aout and help them.....we can see they are in pain.and who do we blame?.....family upbringing or some trauma that must have happened. If the case worker is so wrapped up with this child, let him take him home and leave him with his own kids.