These types of incidents used to be carried out typically by middle aged white males who were stressed, frustrated and felt passed by or failed to live up to hopes and expectations. Recently they have been more typically associated with young Gen Y maies who don't fit in socially or feel like failures. And a lot of them are killing other innocents simply because they can't get laid. Cho, the V Tech shooter, fit this category and there have been a number of others. It likely contributed to Lanza and the Colorado dumbass movie theater shooter.
This appears to be a generational phenomenon; more than a few sociologists have suggested that the entitled, molly coddled, everyone gets an A or a trophy world these grew up in has contributed to these slaugters. Little Johnny never got to experience not making the team, not getting a trophy or failing and didn't develop the skillsets or mindsets to deal with failure. I concur. This 22 year old fits that mold perfectly. There are of course other contibuting factors, such as mental issues, etc., but a lot of these young men simply are angry that they don't have more Facebook friends and get laid more often. Sad.