why do killings happen?

It seems like in our society we advertise to much about guns and thing. in video games it always seems like it is about trying to kill someone or there is a gun involved in the video game. Our society advertises to much that killing is an OK thing. This is why there are so many shootings and things. Also it seems like if someone has a problem it is just swept under the rug like everything is OK. At our school it seems like they don't really care about how the person feels it seems is just about how our school looks to others. So many people just think if they act like nothing is wrong then the problem will just go away, but when really the problem will just get worse. This is how things like Clumbind happens. I think we should do more as a whole to help people with their daily life problems and try more to prevent things like this from happening in the future.