*EDIT* What would you do if you thought your child was a psychopath?

How does one handle this? Please be specific as if this was happening to you.

Edit:

This is not my child, but my cousin who I was very close to as he grew up until the last few years. He's 10 now. He's killed animals in front of me when he was 7. He has this emotional disconnect and only what I can explain as autism like behaviors. He doesn't understand basic math like addition because he doesn't try whatsoever. And he says things like "what would a bat look like if I shot an arrow through it. I know it'd be dead but what would it look like?" I'm afraid that he might start stealing or something like that soon because of his extreme disinterest/rebellion towards school. I have brought all of this to the attention of his parents. They know how he is. But they think he's normal and considered everything I said to be a "boys will be boys" type of deal. I love him but he's not getting the help he needs and deserves and I'm afraid of what kind of member he will be in society.