EDIT: Added for parents. As one needs to speak the lingo to get through to some of those who are not forthcoming.
In different settings, the term Functional Assessment is CFA, with the word Comprehensive before the term. This entails testing that will get to the real situation regarding learning levels, weaknesses and strengths, the ability to follow instructions to have successful outcomes, and IMO, a liberal mindset.
And regarding my comment above on police on campus, where I saw the biggest improvement with those who had troubles complying or problems acting out, the key was empathy. In the case in the OP, there was little or none, or poor education of the school and police and no empathy.
At least the young man has an involved family, even though they may be stressed both by finances and the social isolation that bringing up a disabled child can lead to happening. For such parents, the school should be a lifetime and network of help, not a detention center. I've seen some of the best and the worst.
I wish the ACLU or some other group would investigate the rights of disabled children and the great disparity across the country. Most of it is from designed chaos through budget cuts. It's really a denial of the humanity of these children.
= new reply since forum marked as read