They are a counter terrorism mechanism and in my experience the referral wont have been taken further by them but will have done by whoever referred him to them in the first place, so at the same time as Prevent referrals, there will have been liaison with CAMHS, education, social services
I think whats likely is that there was a lot of concern and recognition of the risk but as I have said in many a post, what do people think will have, or should have actually happened? What do people mean by intervention - forced medication, sectioning, criminal justice route?
And unfortunately none of those are able to deal with behaviours that he had, like many children do have (knife crime, attacks on others including attacks on adults, sexual assaults on others) and the reason for that is that we dont lock children up, there is a move away from criminalising children, we dont have the appetite for sectioning children with ASD, its seen as counter productive but equally he has have a MH disorder, diagnosed and considered detainable, taking a child like this into care doesnt just 'fix' him, he would be the same in care although DOLs could have been considered but Ive already said earlier why those mechanisms are often ineffective.
I also suspect like many kids who present like this, that his obsessions fluctuated so at times he wont have posed such a risk compared to others and so when interventions were looking at more severe interventions he wont have met the threshold
I think people need to be honest with themselves and be clear about what they are expecting should happen in these cases. Ultimately we are saying that children like this should be detained in those circumstances, before anything like this happens, however there isnt the appetite for that.