What are the causes of the Youth violence?

Recently, In the US, a 15-year-old student opens fire on his classmates, killing 2 and injuring 13.
In France a teen boy of 14 yo beat up a teen girl of 12 until she dies because of a love affair story that has gone wrong.

SHOCKING incidents like these are not isolated. Youth violence is a major problem in our society...
... But what are the causes of the youth violence?

The Cause of these incidents are probably a common misunderstanding between them. Teens tend to have misunderstanding on their peers most of the time and they tend to take revenge so easily just in a snap. Maybe the environment where they live is also a factor in which youth violence will cause. Lastly is Media, Nowadays Children and Teens from 6-16 years old are trying to mimic what they see on TV or Internet , probably being a superhero or such like that. Media can influence Youth Violence also.

I think lack of guidance of old ones. If a child is raised in a loving and caring family, they will not be even think of violence. I know there's a lot of factors why young generation nowadays becomes so violent. Media, environment, peers and even family. Proper guidance with them is a big help.

it's 100% parents guilt. How did they got a weapons? Probably the father had a gun (guilt to the parents because they didn't hide the gun correctly). If they got it from somewhere else, it's parents guilt (for the most part), because they aren't controlling their "children".

And parents that give good education never create a child that is already kiling when they are teens.

It's sad that things like that happens in our life. I think perhaps, use of drugs, causes them to act irresponsibly. Actually it could be caused by underlying deep trouble. Perhaps they have no one to turn to. Some youth wouldn't tell anyone of their problems, especially to the parents. I believe if their concerns were probably addressed, incidents like this could be prevented.

I blame it on the parents. first of all, they should NOT let their kids even close to a gun unless they are completely trusting in them.

its not the drugs, its the mistreatment by others that makes people use the drugs to get away from life.

i think this is all depend upon there culture i think in india it is not happening specially there parent should take care about them