It is tragic that Stephon lost his life, this has to be every parents nightmare.
Autism (including Aspergers Syndrome) is a SOCIAL COMMUNICATIONS disorder. This means that people affected by autism do not understand social rules and that autocratic means of handling them DO NOT WORK.
They also struggle to COMMUNICATE what is bothering them.
Autism is an anxiety based disorder, so if you can understand the anxiety the person with autism feels you can try to address it. You can never do that with a gun.
If Spephon had an issue with going to school it would have been because he had a negative experience that created an anxiety for him. I have known autistic kids completely refused to go to a specific school and for it to take 7 months to get them to trust another school.
Autistic people are disabled, you would not punish a blind man from tripping over something he did not see.
When an autistic person is in a state of anxiety you cannot reason with them or force them to do anything, the best approach is to back off and give them time to process things, then approach them with a friendly person they trust who can then try to address the anxiety.
With autism being diagnosed in one in 88 children, the police need to be be training about autism and how to best deal with a person who has been affected by autism.
Mostly they should not apply force or pressure because it will only make things worse, better to bring in a mediator or support person and back off.
We see these kind of injustices the world over, I can only hope that some meaning can be put to the tragic death of Stephon, perhaps if it results in greater understanding and tolerance in our society.