Another senseless mass killing

The reports are coming so often that we are becoming enured to them. A truck driver plows through a crowd in Nice, France, killing scores of people. A gunman goes on a rampage in Germany, killing nine at a shopping mall.
Each time there is a mass killing, whether on U.S. soil or abroad, our nation launches into a renewed and more heated debate about gun control.
A man plows through a crowd with a truck, and those against gun control tout it like a victory — see: the problem isn’t guns. A shooter opens up at a mall, and gun control proponents raise the event up like a red flag warning to prove that more gun control is needed.
Somehow, these mass killings have turned into a contest between the two sides of gun control.
Just once, we wish the experts would stop debating gun control and start looking at the much deeper, and much darker, issue: why are so many so intent in harming their fellow man?
What compels someone to take a gun to a school, bomb or fly a plane into an occupied building, or drive a truck through a crowd of people?
Maybe the reasons are as unique as the people who commit such crimes. But such incidents were rare until recent years. What has changed? Is the immediate media attention? Are mental health issues more prominent that we think? Are people just that much more ideological and violentally committed to their beliefs?
While each perpetrator is unique, there must be some common thread, some identifier, that will help us find the root of the problem. Until then, we expect these incidents will keep plaguing our universe.