The overwhelming presence of guns in the United States is the result of an arms race -- a three-way arms race. Potential gun owners are persuaded to get guns with the newest technology designed to be more deadly in each generation. Much of the persuasion is by showing use by the idealized warriors of law enforcement agencies. These agencies are pressured and encouraged by their members and by industry get for themselves more extreme weaponry than the most outrageous real or imaginary "bad guys." And the actual criminals and lawless persons strive to keep up their image on the street while they get guns from gun owners and businesses by theft or diversion.
This triangle has become a cycle where each group drives the next into being ever more armed. The arms industry and gun culture media work to energize the cycle at each step; although they would deny deliberately encouraging the illegal armament of criminals. The important thing about a cycle is that every stage depends on all the others and it can be speeded or slowed at any point.
I'm going to start with law enforcement and it's effect on gun sales, interest and ownership by the public. As agencies have built up their firepower, the newsstands have been populated with slick magazines showing it off such as Harris Publications' Special Weapons for Military and Police. Many items such as submachine guns, short barrel shotguns and rifles and silencers are regulated by the National Firearms Act (NFA) and require an expensive and difficult to get license for civilians and a substantial tax on each transfer. There has been a movement to expand the possible weapons that citizens can have without such regulation. Several states have passed laws such as the Montana Firearms Freedom Act that would override federal law and allow possession of such weapons made and held within the state without federal regulation. These laws are currently untested in the courts. At the same time manufacturers have employed a battalion of engineers to design weapons that are technically outside the NFA definitions but extend both actual firepower and aggressive appearance to new levels. A popular example is the KSG bullpup type shotgun such as the one recently returned to George Zimmerman. The non-NFA version for most non-law enforcement sales is built to the NFA rule and has the barrel extend deeply into the stock to meet the 18-inch barrel length minimum. It has two ammunition magazine tubes for double the number of rounds. But Guns and Weapons for Law Enforcement features the "sawed off" version. Bullpup and this KSG design is the new more aggressive shotgun. It's way beyond the Remington 870 used by the Navy Yard shooter who already could add ammunition to his gun at any time by just shoving shells into a hole. No need to change magazines for an indefinite shooting spree.
All of this technology and hype is exciting to a lot of people looking for something to put their time, interest and money into. Shooting can be a lot of fun. It's been decades since I was in the Army and fired heavy-duty arms, but I remember it well. There is lots of company and places to go and something new all the time. Hobbyists in general are obsessive and gun hobbyists especially so. They take in the media material and talk with their shooting friends and rush down to the gun store and buy loads of the new exciting models. The frenzy has only expanded since the tragic shootings at Sandy Hook Elementary School and the expansion is still going.
All of the guns that cause trouble start out legally. Sometimes an owner turns bad but mostly guns are stolen and diverted to get into dangerous hands. The exceptions are small; gun smuggling is an export industry in the U.S., homemade "zipguns" are interesting but rare and losses from law enforcement are much smaller than the hundreds of thousands of guns stolen from dealers and users each year. The 3D printers in the news lately may create a problem with detectability but are way too slow and crude to be a factor in our mass gun problem, at least for the next decade or so .
A lot of our gun deaths and injuries come directly from guns in legal hands. Accidents, domestic homicides and especially suicide usually are from legal guns. But the big problem of so many nearly unregulated guns is that they go from legal to prohibited hands. A giant hole in the background check system allows any prohibited person to buy whatever he wants as long as he doesn't use a federally licensed dealer and winks when he tells the seller he's OK. Some states make it tougher, but there are no checks at the border between states and guns flow like water. Stolen guns are the other main source of guns going to criminals. The FBI gets reports of over 200,000 guns stolen per year, and it's likely that reports don't reach the FBI in most of the cases.
Illegal gun users such as gang members see the media hype too. They are looking for respect mostly from each other. When the media write about gun crimes, they focus on the most extreme examples. Just looking at DC, which is near to me, we have events like 12 killed or 13 injured in the last year and many smaller ones.
Law enforcement agencies have adopted service weapons with a large bullet capacity in order to be sure to have more than anyone they could possibly confront. They receive funds disproportionately to face rare but extreme confrontations. It seems that every agency has to have a SWAT team no matter how small the jurisdiction. In smaller and medium cities there is little for such teams to do and they have to justify their existence. So they don't wait for a hostage situation but they become proactive and serve warrants. While I don't usually agree with the Cato Institute, I am amazed by their map of "Botched Paramilitary Police Raids." Publicity hungry Sheriff Joe Arpaio has obtained and shown off the the press a belt-fed 50 cal. machine gun. Agencies get the weaponry for the funding, for show and for fun, but the process is driven by a perception of ever better armed adversaries. They, unfortunately, focus on rare extreme events such as the North Hollywood Shoot Out of 1997 where nearly 2000 rounds of ammunition were fired or the rogue ex-cop Christopher Dorner who had a 50-cal. Barrett sniper rifle.
So the cycle goes on and gives us a greater and greater number of more and more deadly weapons. To restore some sort of sanity and reduce the carnage, it will be necessary to slow this process at each corner of the triangle. We can get better leadership in our law enforcement agencies that works to stop the game of getting more and deadlier arms than actually needed. Leadership that takes command and recognizes the effect both inside and outside the agency of militarization police. We can regulate private ownership of guns to eliminate unchecked purchase and limit the most unsafe weapon types. We can block the diversion of guns by illegal sale and by theft. A good way to stop diversion is to require that gun owners have insurance that pays victims and remains responsible if guns are transferred by theft or otherwise to uninsured parties. Because this problem is a cycle, improvements in policy at each point will have a cumulative effect.