Not going to /pol/ since that place is full of nuts

Does anyone else feel like the sentences and public narrative towards school shooters, especially young ones, is just a bit too strong?

Of course the murder of innocent students is fucking awful, but I feel like they intentionally ignore the mental health aspect. Is a 15 year old boy who very obviously suffered from psychological problems really fully culpable for said crimes? Perhaps I'm being too naïve here, but I've always felt that putting them in rehabilitation facilities for a good few years would be much more logical than just throwing them in prison for life.. They still have a chance at life if their mental problems are solved, or hell even prevented. Why is the administration of schools not being looked at to find the root of the problems regarding student relationships? Why are we automatically assuming clean mental states for these kids? What is the purpose behind locking them up for life? Why not put them on medication, get them the psychiatric help they need, and let them hopefully put it behind them? It just seems needlessly cruel as a punishment towards a literal child.

I really want to have this discussion, and I wasn't sure where to put it