KNtoran, I think you are right about the norms and values in young people's lives.
A couple of generations ago you didn't need to lock your door in most parts of Wales. What do you do when confronted by a gang of teenagers in the street?
We have some locally, my reaction is to actually talk to them!
Usually you find they are relived to be treated with respect.
They then respond in a similar fashion; what we need to do is listen to young people and give them a voice. They usually carry weapons when they feel threatened, empathy is what is needed. There are a few rotten apples in every barrel, but give the rest a chance.