One of the reasons gun debates are so difficult to settle, aside from the strong feelings involved, is that the data involved in researching connections between gun laws, gun ownership, gun crime and non-gun crime are frequently mixed, murky, misrecorded and difficult to compare [sources: Kates and Mauser; Zimring; Zimring].
Take the United Kingdom, where ever-more stringent gun bans brought gun-related homicides to among the lowest in all of Europe from 2003-2010, but where guns remain widely available and are increasingly used in the commission of violent crimes [sources: Bamber; BBC; Malcolm; UNODC].
How does one interpret the success or failure of gun laws in a nation that a July 2009 issue of The Telegraph dubbed "the violent crime capital of Europe"? The U.K. newspaper based the claim on a 2007 study of per-capita violent offenses, but some people argue that problems of definition render comparisons among the European Union nations invalid [source: Edwards].
Similarly problematic is the claim that dropping crime rates in America throughout the 1990s were attributable to the relaxation of gun control policies [source: Kates and Mauser]. Perhaps this easing was a factor, but no data exists that can draw so clear a line, particularly when other factors were in play. Some analysts, for example, point to the significant uptick in American prison populations and executions during this period, or to the larger police forces and improved crime-fighting tactics, the flagging crack-cocaine trade and/or the booming economy [sources: Donohue and Levitt; Lott and Mustard].
Other analysts take more unusual tacks to explaining the drop-off. Economist Rick Nevin, for example, attributes a substantial portion of crime rate fluctuation to changes in childhood lead exposure [source: Vedantam]. As made famous in the book "Freakonomics," economists Steven Levitt and John Donohue credit legalized abortion in the 1970s for the 1990s fall in violent crime. They argue that abortions prevented the births of children to poor, single, teenaged mothers -- a demographic they say is more likely to produce criminal offspring [sources: Donohue and Levitt; Kates and Mauser; Levitt and Dubner; Vedantam].
The point is, the "more guns = more violence" argument and the "gun ownership = decreased crime" argument both sidestep the complicating socioeconomic, cultural and psychological factors affecting violent crime. Economic disparities within countries, along with periods of economic downturn, drive up crime and homicides, and violent crimes occurs four times more often in countries with wide income gaps. While economic prosperity tends to decrease violent crime, crime itself can depress community development, perpetuating a cycle of poverty and violence [source: UNODC].
Violent crime arises from more complicated causes than guns, yet there is no question that guns are associated with a particularly brutal brand of crime. Removing guns from the equation might not stop violence altogether, but might it prevent another Newtown?