Mental illness as an autistic child.

A lot of serial killers and such start off with hurting animals. To Ward's point it's important to figure out why your son likes taking apart animals... if it's because he likes seeing how different parts work, and wants to figure out how things work, a good behavioral specialist could work with him to rewire his reward centers to things like taking apart computers, clocks and other mechanical objects. You can essentially transfer the pleasure he gets to more benign activities. It's true for everyone, but from what I understand especially true of autistic children, it isn't enough to forbid certain activities, you have to transfer them to other activities.

I can say with certainty he doesn't care about how things work. It's more of a 'signs of damage' kind of thing. He likes seeing the aftermath of the destruction he caused. There are a lot of holes in my drywall from that. Also, he threw eggs at the neighbors houses (that was a fun time). Drops items off the deck to see how they break (including a dog once). I've tried redirecting him by putting together chunks of legos and letting him smash those. Sometimes that works. The least destructive redirection I've got is him simply pouring a cup of water from the deck to the patio. The splash of the water seems to calm him a bit. He has a major attraction to water.