We have a young lad where I live, who witnessed his friend getting stabbed and unfortunately died.
He now does an amnesty and people contact him and willingly give up their knives.
I honestly believe the world is turning into what is it, as we now need two parents working 40+ hours each, just to survive, so our latchkey kids are getting involved in things they shouldn't and getting into situations they are too immature to understand, only way out being violence.
The one thing he has said is, most knives carried are your good old kitchen knife, as easily accessible. Knives should therefore be stored in a block, so you can realise one is missing, if left in a drawer with other stuff you wouldn't notice it gone.
Kids carry them out of fear of needing protection, yet, then are more likely to use it.
It's sad and terrible at the same time.
My kids secondary used to bring in metal detector arches (like at airport - not sure what they are called)at random times and every child had to walk through to get into school. Surprising what got detected.