Mental illness as an autistic child.

Like a key thing. What is the motivation for the killing? Is he killing on a scientific and clinical level b3cause he's curious? Or gets pleasure/excitement out of it. I.e. the act. Really only a psyche doc can properly evaluate that. How functioning is he with his autism?

Sorry if I'm being too blunt. Mental health issues suck. I've had a kid who had to be baker acted (72 hr hold) twice, but is much better now. His was more about sexuality and gender identity. Long story for another day.
Sometimes the impulsiveness in ADHD can be an enormous problem. We’ve all had crazy thoughts before, but we have the ability to rationalize. Some kids ADHD is so bad that any crazy thought must be persued because they don’t have the ability (or struggle significantly) to suppress it.

Believe it or not, the number one associated diagnosis with childhood suicide is ADHD. Part of that is likely prevalence of the ADHD diagnosis, but another part is impulsivity.