The real issue is that the states have closed the institutions. Instead, the states are placing young people who need institutional care into the schools.
That is what happened in this case.
From what I recall:
He really is intellectually disabled. His parents adopted him as an infant, and they homeschooled him. But, when he grew big and strong, they could no longer handle his outbursts, so they placed him in an institution.
But, the insurance company refused to continue paying for his institutional care, so he was sent to a group home.
But, the group homes put their young residents into the special ed programs in the public school system. That is, the states have been using the public school system as “day programs” for intellectually disabled young people.
Brendan’s own parents argued that he should NOT be put into school, but he was placed there, anyway.
And now look what happened.
He was NOT the first special ed student to attack an aide in this school system. Two others (both white and older than he is) attacked aides there. Neither was sent to prison. IIRC, both returned to their group homes.
Aides have been attacked in other schools, too. At least one aide was killed, but no one is paying attention to that case.
He should be living in an institution - NOT in prison.