It seems that more and more reports with this or similar statements have been coming out about the recent shooting in Connecticut; with some of the biggest articles being released by “The Sun” and “The Daily Express” (UK tabloids). 
The insight was given by the family’s plumber Peter Wlasuk : “The boys were fans of the military. They had posters all over the wall in the basement. They had one poster of every piece of military equipment the US ever made. (…) It was a huge poster with every tank ever made. The kids could tell you about guns they had never seen from the ’40s, ’50s and ’60s. The kids who play these games know all about them. (…) I’m not blaming the games for what happened. But they see a picture of a historical gun and say ‘I’ve used that on Call Of Duty’.”
It was furthermore stated, that 20 year old Adam Lanza (the shooter) “spent hours playing bloodthirsty computer games – such as Call of Duty – in the windowless basement of his mother’s house”. 
Before I give any of my personal input to this story, I would like to share a few related happenings with you, which have been going on for years in Germany now. I have been following the same kind of headlines over here as well.
There was a shooting just like this in multiple parts of the country , one of them being in Winnenden (Germany) some time ago. Not long after they reported about it, media tried blaming videogames for this too. 
Tim K.’s (shooter) father was a member of the gun club and had 4’600 shots with a heavy-calibered weapon casually laying around in his bedroom (as opposed to it being stored – just as the law specifies – in a safe!). Furthermore, Tim also had some mental issues. 
Here in Germany we have laws that state that “very violent games” can not be sold to persons under the age of 18 (equals legal age over here) and some titles are even completely banned or at least heavily cut / censored. For years now, the politicians and “experts” have been debating about completely banning violent videogames – or how they call them here – “Killer Games”.
During a survey presented by KFN-director (criminological research institute of Niedersachsen) Christian Pfeiffer, they asked 44’610 9th graders about their likes in terms of internet- and computer games. 4,3% of the girls and 15,8% of the boys show an “excessive play behaviour”, which means that they play for more than 4,5hrs a day. 14’000 9th graders have been labelled “addicted” and another 23’000 are “prone to addiction”. The total of videogame addicted youths has been estimated to be between 50’000 – 60’000. 
If we look at the provided graph on the source website, we can see that – on average – a 9th grader spends their day as follows :
~ TV / Video / DVD – 213min (m) | 201min (f)
~ Chatting On The Internet – 103min (m) | 113min (f)
~ Videogames – 141min (m) | 56min (f)
~ Sports – 109min (m) | 77min (f)
~ Family Activities – 65min (m) | 79min (f)
~ Going Out (Movies, Disco, Bars, Events) – 64min (m) | 70min (f)
~ Reading Books – 25min (m) | 43min (f)
~ Make Music – 22min (m) | 25min (f)
~ Engagement For Environment / Politics / Social Affairs – 9min (m) | 10min (f)
I am aware that this is just a “daily average”; that it’s only for 9th graders and only for one of the states in Germany (not America or anywhere else), but I am sure that if you would look up a graph for your area or even made a study amongst your peers, you’d get a similar result.
Let’s look at the amounts and rankings for a second.
I personally immediately notice that – from a psychological standpoint – the stuff that would really help to develop a child’s personality and sense for “togetherness” is on the bottom. I am talking about family activities; reading books; sports; going out; engagement for anything but yourself.
If I may interject my opinion on what I have actually noticed about today’s kids, it’s not that the bad, bad videogames make them all screwed up; but instead it is the lack of proper education from parts of their parents that is really not helping things.
If we think about it, a parent should sit down with their kid and do things together; teach them the things it will need in life and not just park it in front of the so-called “tech-babysitters” such as TVs or computers.
I used to watch a lot of documentaries about families and I also read through a lot of online forums, and what I keep seeing is that a lot of parents are either just absolutely overwhelmed with how to *properly* raise a kid or just don’t care, because “it wasn’t planned, and honestly the kid only interrupts their life, so might as well make it as easy as possible and park it in front of the TV”. This is the sad truth and we humans are very prone to taking the easy way out, which during or after such shocking events (the massacre / shooting) would be to just use something that can’t even stand up for itself – in this case: the videogame industry.
I agree that for some people, a videogame can have a really bad influence, even more so if they are already mentally challenged and maybe have some very overwhelmed parents (preferably who have guns just laying around in their house openly and who won’t take an interest in their kid either; leaving it by itself and pretty much alone / abandoned), but we can’t just generalize like this and have to look at the individual cases.
There are indeed some scientists and specialists that are looking into how else videogames affect a person. Some even say that said media can reduce stress  and depression ; other experts at least state that “playing ‘those kinds’ of videogames is a symptom, not the root” and they also say that the perpetrator in question often either has problems within the family; school or alike, but is unable to bring them up ; hence why he often flees into the virtual world.
In contrast to the recent discussions from the US and a lot of countries in Europe wanting the “Killer Games” banned (such as Switzerland, which passed “Bill 09.3422” that defines them as “Games, in which gruesome acts of violence against humans or human-like creatures contribute towards the game’s completion” ), we should also take a quick look at Japan, where videogames are not just a hobby, but a lifestyle. 
Asians have been reaping the benefits of this media for ages and also like using them as “unwinding tool” in a social environment after getting out of work or school. It is thus not surprising that arcades are still blooming and are a very well-liked and popular hangout that can be enjoyed together with others. 
I feel that if you let a kid use any media in such a responsible way; possibly help answering questions it may have and even play certain games together, a lot of “reality-loss” can be avoided.
Italy has a really interesting system since a few years for movies, where a light on the screen with a specific color indicates if the currently shown program can be watched by the child alone; should be watched with an adult present or skipped out on completely. Similar ideas have been applied to games in some countries; however the ultimate control and decision should rest with the parents.
Spending more time with the family is mandatory and healthy, so a videogame doesn’t have to be just a “tech-babysitter” and leave the player confused, twisted or even worse; trying desperately to make up for lack of love from blood-relatives and friends, or as a method to cope with stress from school.
Let’s treat videogames as a helpful tool and as a form of art and entertainment; not a scapegoat for mistakes we have made in the education of our family or to make up for lack of care towards our friends.
Special Thanks To [IceB]!
 – http://eurogamer.net/articles/2012-12-18-uk-tabloids-single-out-call-of-duty-dynasty-warriors-in-coverage-of-sandy-hook-school-massacre
 – http://welt.de/vermischtes/article3361746/Amoklaeufer-spielte-gewalttaetige-Videospiele.html (German)
 – http://welt.de/politik/article3386801/Einen-Amoklauf-lernt-man-nicht-durch-Counterstrike.html (German)
 – http://economix.blogs.nytimes.com/2010/05/24/do-video-games-equal-less-crime/
 – http://gamestar.de/news/vermischtes/2316344/gewalt_in_spielen.html (German)
 – http://sueddeutsche.de/panorama/ursachen-von-amoklaeufen-was-killer-und-killerspiele-wirklich-miteinander-zu-tun-haben-1.1438225 (German)
 – http://gamestar.de/spiele/half-life-counter-strike/news/schweiz_verbot_von_killerspielen,33806,2313585.html (German)
 – http://gamespot.com/news/pax-07-japanese-gaming-culture-101-6177668
 – http://acapitalwasteland.com/2012/11/why-are-arcades-so-damn-popular-in.html