Online weapons shopping for the 21st century. A short 8 minute drive South from Aurora's Century Cinemas on Abilene St. brings you to Gander Mountain, a sporting goods and weapons store where you can buy assault rifles for as low as $500-600. Photo from: www.gandermountain.com

A short 20-minute walk north from the Century theaters in Aurora, Colorado, will bring you to a gun shop that sells AK-47s, some for as low as $759.95.

An 8-minute drive in the opposite direction will get you to another store that sells a Kalashnikov for $599.99.

Other assault rifles offered by the two stores sell in the low thousands. 

How easy is it to get such a weapon in Colorado? A 15-minute background check on the store's link to the National Instant Criminal Background System will reveal whether the purchaser has a felony. Those without such records, over the age of 21, including those from out of state (except from New York, Illinois, and California), and carrying a valid government-issued photo identification can become the proud owner of a new high-powered assault rifle.

James Holmes -- who had no criminal history and was an Aurora resident -- would have met the necessary qualifications demanded from the state of Colorado to purchase one of these weapons. In the early morning of July 20, 2012, he allegedly used one them to gun down unsuspecting moviegoers in Aurora, a place that couldn't be farther away from where such weapons are more commonly used -- the mountains, deserts, jungles, and swamps of the world's conflict zones.

Earlier reports from the media are saying the weapon used by Holmes was an AK-47 (conflicting reports say it was instead an AR-15, essentially a version of the American-made M-16).

If it was, then add another dozen from America to the AK-47's kill score. With one caveat: when the weapon is being pointed at Americans, usually those holding it aren't fellow countrymen.

The Kalashnikov is found on national flags, in the hands of children, and is perhaps one of the most ubiquitous machines every created by man. There are some 100 million copies worldwide. It has likely killed millions -- who can know for sure how many since its birth nearly 70 years ago?

But if the AK is getting new attention in the U.S., over the past year it has undoubtedly killed many more in other countries around the world: Syria, Mali, the southern Philippines, Yemen, Sudan, Somalia, Pakistan and Afghanistan. The list could expand to include every conflict zone on the planet.

Of the hundreds of millions of firearms in the world, experts have estimated that nearly a fifth are Kalashnikovs.

The Kalashnikov's resiliency and intuitive ease of use make it one of the most effective weapons ever made by man. Its reputation for ruggedness -- being able to fire in freezing and blistering hot conditions, even after being submerged in mud and water -- is world-renowned. Soviet designer Mikhail Kalashnikov created the weapon in 1945,  first distributed to troops in 1947 (hence the name). It was considered a revolutionary design. In subsequent years, it was transferred to Communist allies, reengineered, redesigned, refined, and built in dozens of variants.

When the Eastern bloc collapsed more than 20 years ago, stockpiles of the rifles were sold at bargain prices, helping to fuel the newly emerging ethnic conflicts cropping up in the global south.

But how cheap is the weapon, really? Phillipin Killicoat of Oxford University estimated in 2007, writing for the World Bank, that the gun cost only $150 in 2005 in conflict zones in Africa. In the Western Hemisphere it can be bought for approximately $600 on average. A price tag less than a flight from coast to coast could deliver you one of deadliest weapons made by man, favored by the Taliban and insurgents everywhere.

The increasing trade in illicit small arms across the world in recent years has likely deflated the price, and made it much more affordable than ever.

No surprise, then, that essentially the same weapon used by child soldiers in northern Uganda can also be used in the Rocky Mountains to shoot at children inside a movie theater.