I will be very very surprised if someone who did this had absolutely no history of behaviour problems before this.
Only got to this post and NRTFT but one of the things we could do is properly fund schools and early intervention with boys (and some girls too) that exhibit aggressive tendancies. At the moment schools are in crisis mode. Not enough school places for disturbed children in PRUs. https://schoolsweek.co.uk/the-excluded-children-with-nowhere-to-go/
At the moment all that happens in the more extreme cases in schools is exclusion - often what the child wants - and if the parents aren't exceptionally resilient and resourceful they can fall off the radar if there aren't places in PRUs and end up being 'taught' online - and presumably spending more and more time online with perhaps very little restriction on what they're viewing (if parents have to work etc).
There needs also to be some degree of punishment for early transgressions so children understand that there will be unpleasant consequences. Removal of mobile devices, for example. I know a lot of people don't agree with this, but I think it would end up saving a lot of children. Of course in an ideal world, each child would have a tailored educational plan and 1 to 1 support but until that mythical situation exists, sanctions are better than letting them go further down a bad road.
And it's reflected in the adult population too - at the moment in this country violent men get away with a lot before they're finally locked up. See Wayne Couzens - reported for flashing before he killed Sarah Everard and the police did nothing, if they had taken action on this crime, Sarah could well be alive today. We need a societal culture where we don't allow the police to overlook crimes like this. Zero tolerance around aggressive behaviour in schools, more places in PRUs. There's a lot that could be done, none of it is easy though.