The question is about the eagerness of Americans in general to kill each other.
Yes, the availability of guns makes the matter much, much worse but that isn't the entire story.

We can have this discussion without getting into the 2and Amendment hassle.
What is it about Americans that makes us so violent?

There are other nations on the earth where they have plenty of firearms and not nearly as much violent crime, though so there's a necessary discussion of the American Culture. But it's entirely possible that our need to posess a lot of guns ties into our need to be violent.

I don't think we have any real community in America and haven't for a long time. Each man is an island of self interest, and we've developed philosophies and social movements to confirm that belief. Having determined that freedom is a positive good (and it is), we have elevated that to the exclusion of all other social virtues. Given that, it's not surprising that we will stoop to any method to preserve our freedom - including shooting each other over perceived threats.

Bryant

I shot him because "I thought he had a gun," or "He was reaching for his (later to be found non-existent) gun," or in the case of a child killer, "It looked like a real gun."

If we didn't have so many guns in our society, chicken-shit cops could not use it as an excuse for their chicken-shittedness, and then perhaps we 'd find these fraidycats/bullies earlier and get them out of the police force before they kill people and give brave, honest cops a bad name.

I think that it is not the US that is exceptional but rather Europe, and I would think their aversion to violence and guns and murder might tie in to the fact that last century Europe was sort of a bloodbath much of the time.
US murder rate 4.7 per 100,000. Jamaica, 39.3. Honduras, 90.4. Venezuela 53.7.

Of course no one would ask 'what's wrong with Argentinians, 5.5 murders per 100,000 people, what makes them so violent....because some folks see America as exceptional in the negative and the positive.

There's a lot to say. Our country's size, population size, heterogeneousness, immigration patterns, regionalism, approach to conflict, and other issues all figure in.

alludes to the saying 'As American as Mom, baseball and (apple) pie."

I'm glad you live in a non-violent neighborhood.

Yes, we have worked very hard to keep our neighborhood safe. We have a wonderful citizens patrol
who "Ain't afraid of Nuthin"...and that's just the WOMEN !!!!!..lol

and we hire psychopaths to "enforce the laws".

For one, we have 300 million guns in this country. That's enough to arm every man woman and child. If you're a cop you are being trained that literally everyone you encounter in public -- whether it be an 10 year-old child in a wheelchair -- or a 30 year-old woman -- is packing heat. Your average cop is conditioned to be paranoid and fearful before their first real day on the job.

Additionally, I believe the military influence in police training techniques over the past 20 years has encouraged a shoot to kill, empty the clip into their face, mentality no matter what the situation is. Basically, when they pull out the gun someone is going to die. You don't see a lot of cops winging people these days. They shoot to kill 100 percent of the time regardless of what the situation is.

Third, the class of people who enter police work has generally declined over the last 30 years. Now it's mostly ill tempered meat heads who are ill suited for any other kind of work.

What amazes me is that shooting seems banal here. Neither Wilson, nor the police chief in Jefferson expressed the slightest regret that Michael Brown was dead. For them, it was a no-brainer. Same thing in Cleveland. Same thing with the man who was shot in a Walmart.

Even if they perceived a danger, they could have tried to deescalate, but no. Their first reflex was to shoot and talk after.

This is why it was so important that Wilson was indicted. Because killing a man should never be something banal.

Related to police brutality.

2011 England riots

Date: 6 to 11 August 2011 (although incidents remained ongoing after this period)
Location: Several districts of London, Birmingham and the West Midlands, Merseyside, Greater Manchester, Bristol and several other areas.[1][2]
Methods Rioting, looting, arson, mugging, assault, murder

http://en.wikipedia.org/wiki/2011_England_riots

I would blame American individualism. You could arm everyone in a country like Japan to the teeth and you still wouldn't see anywhere near the level of violence as you do in the United States.

People in many other countries are taught that while it's important to respect and value the individual, it's equally important to keep in mind everyone is part of a larger group and has a responsibility toward each other, for the individual cannot survive and prosper without the collective.

Meanwhile, in the United States it's all about me, me, me, most of all by far among our conservatives and libertarians, who try to convince us that the individual cannot survive and prosper with the collective.