My sister's youngest son, 16, has been having a lot of violent outbursts. He gets upset over small things and flies into rages. He tears stuff up, puts holes in the walls, slams his head against the wall, and threatens to kill my sister. The last time it happened she called the cops. They took him to the ER and the ER refused to treat him because he was so violent and because they don't have insurance. The nurse said he had "cold" eyes and she believed he really wanted to kill my sister.
I've been concerned about my nephew for a while. For a few years I've gotten a weird vibe off of him and I've wondered if he might be a sociopath. AFAIK he hasn't killed or tortured any animals, but he did cut the whiskers off a cat "just because."
He lived with his dad until a couple of years ago (court ordered). Once he was old enough he went to live with my sister. At that time his dad basically self-destructed and succumbed to alcoholism, quit or lost his job, and now sleeps on his sisters couch and has zero contact with them.
His dad was also given to violent outbursts, which is why my sister divorced him.
My sister is trying to find some way to get him treatment, but without insurance it is basically impossible.