For the last two decades or so , thru the extensive studies , more scientists and legal experts , trying to recognize neuroscience predisposition among people , who could kill other human bean without any mercy and regrets . They found , that many individuals ( and majority of them served as a soldiers ) were stimulated by hidden killing gene , responsible for inverted mind set , which allows them to act beyond control and commit ruthless crime(s) .

Humans , as a species , still carry hunting instinct , which thru the evolutionary process didn't rule out possibilities of taking someone's life - legally or not . This gene already is able to trigger and ignite decision of killing someone without recognition of incoming consequences . For them , principles of life in symbiosis with others do not play any major role . Behavior of many doesn't possess ability of self judgmental thinking , or don't recognize the differences between right and wrong . Interpretation of moral rules of life comes from many levels ; has also many roots , like : ethics , culture , how they were raised , who provided education , influences of environment , etc . Those , who are already violent and easily provoked , can use violence as a form of entertainment too. Sometimes they also looking for the depletion of an anger , which in many cases can't be controlled . Presently , the major causes of violent crime comes from poverty and usually individuals without any hope , or life improvement are the first , who consciously are grabbing THE GUNS , as a tool to allow them to achieve un-consience goal. The main reason of making it so easy are simplicity of reaching for these tools and this is the fundamental subject of our endless discussion.