It's the same mentality as most of the maladjusted young people that carry out spree shootings in the USA.
Basement losers with a grudge against the world and often for unclear reasons.
How can we stop these people getting hold of knives or other weapons and carrying out attacks?
It's very difficult. The prevent system focuses on preventing young people from becoming radicalised and becoming terrorists.
But maybe there should be a wider focus on preventing young boys (and girls, but it's mostly boys) from developing the mindset where they carry knives, admire violence and become involved in the criminal justice system.
I saw parallels with this case. Same age, another black boy with autism and a warped sense of "respect".
Could the killer in Southport ever have been stopped or saved from going down that path? I'm not sure. But maybe he could have been detained in a secure hospital.