His sister woke from a nap when he was about 5, and he had surrounded her with all the knives from the kitchen, all pointing at her.
I seriously doubt porn made him think that one up.

I believe he just wanted attention and probably sympathy at that point.
Maybe he was hoping for prison counselor.

I have avoided a whole lot of low quality relationships because I had porn instead.
I've seen some sick shit also, but never imitated any of it.