@Mame,
I'm not so sure the school bears much responsibility, or even that much can change (from an overall perspective):
- it would likely be a breach of privacy to demand every student detail their gun ownership and access to guns
- school counsellors are likely the lowest qualified counsellors available (and perhaps even teachers with a social work degree as well), rather than psychologists
- a lot of the warning signs are difficult to track (ie. either manpower intensive, or very invasive, or both ie. they create resources and privacy issues)
- a lot of the other warning signs happen at home
That's not to say it's impossible to do - just difficult. And in that difficult space, how do you justify a suspension if you don't have enough facts? Particularly if your government works on accountability principles, and demands you account for your decisions or face discrimination or bullying claims & disciplinary actions?
The reward/disciplinary system is the thing that drives culture the most. I consider resources to be part of that system (ie. if you do not have the resources, there is very little motivation to do something). Same goes if you are very likely to get called to account for something that itakes a lot of work to substantiate, you are much less likely to attempt it.