Growing up, I was always brought up being told that the 2nd amendment had two reasons for being written.
The first was so that each colony had the ability to defend itself from any other colony, or defend themselves from Britain if they ever invaded and the continental army had not arrived yet. The second reasoning for it was to give the people of this new land the peace of mind that the government couldn't just overthrow them. They had the ability to defend themselves and remain free.
I think it's pretty clear that neither of those is really a concern anymore. If the government is going to overthrow the people, it's not going to be with guns. It will most likely be something financial that is executed over a number of years. If the government ever did try to overthrow the citizens of the US with guns, well, that would be the shortest fight in US history. I don't care who you are or how many guns you have, if a fleet of armored Humvee come to your front door, you aren't making it more than 5 minutes.
I don't know what it is, but for some reason, people interpret the restriction and regulation of guns to be the ultimate sign the the citizens of the United States are no longer free. Why don't these people ever bitch about the fact that warrants can now be obtained just because a cop sends a text message with no real probable cause, or that your phone lines can be tapped for virtually no reason, or how about the fact that every keystroke you make on the internet is recorded in a database...
I feel like if someone wants a gun in their home, for whatever reason, let them have it. We do live in a world with sick individuals, and you never know what kind of asshole is coming into your house (Cheshire home invasion). I feel that a gun should have to be registered as a home protection item, and if you are ever caught with it off your property, for any reason at all, you get arrested. I love the idea of "good guys" having guns, but just because you are a "good guy" doesn't mean you are a good shot.
I don't think there is anything gene that causes this kind of behavior either, nor can it be traced to just movies, video games, etc... These acts are a project of societies obsessive fear over death. We have used death as a tool for so many things, and have made it the underlying fear behind every decision a lot of American make. Count how many times a day you are reminded you can die at any moment. I've probably heard a dozen things by the time I got to school today.
I don't know where I was trying to go with that, but I needed a break from reading and ended up ranting. Carry on.