It's not like no one has ever asked them before. There's data everywhere and decades of research. We tracked down the best of it so you don't have to.
Jump to a question:
- How much gun violence is there in the U.S.?
- How many guns are there in the U.S.?
- How do mass shootings differ from other types of gun violence?
- What gun control laws currently exist?
- What could be done to reduce gun violence?
- Would fewer guns result in less gun violence?
- Would gun control result in fewer guns?
- How often are guns used in self-defense?
- Won't criminals kill with other weapons if they don't have guns?
- What has worked to reduce gun violence?
- Are the White House proposals likely to be effective?
- How does the U.S. compare to other countries?
- What don't we know yet?
There were 8,583 homicides by firearms in 2011, out of 12,664 homicides total, according to the FBI. This means that more than two-thirds of homicides involve a firearm. 6,220 of those homicides by firearm (72%) are known to have involved a handgun.
It's worth noting that violent crime rates of all types have been steadily decreasing since the early 1990s. No one is quite sure what is causing this decrease, though there are many theories, ranging from tighter gun control laws to more innovative policing and changes in the drug market. Whatever the cause of this decline, America still has a homicide rate of 4.7 murders per 100,000 people, which is one of the highest of all developed countries (see: international comparison).
Gun violence also affects more than its victims. In areas where it is prevalent, just the threat of violence makes neighborhoods poorer. It's very difficult to quantify the total harm caused by gun violence, but by asking many people how much they would pay to avoid this threat -- a technique called contingent valuation -- researchers have estimated a cost to American society of $100 billion dollars.
Guns are also involved in suicides and accidents. 19,392 of 38,264 suicides in 2010 involved a gun (50%), according to the CDC. There were 606 firearm-related accidents in the same year -- about 5% of the number of intentional gun deaths.
How many guns are there in the U.S.?
There are about 310 million guns in the country. About 40% of households have them, a fraction that has been slowly declining over the last few decades, down from about 50% in the 1960s. Meanwhile, the overall number of guns has increased to about one gun per person, up from one gun for every two persons in the 1960s. This means that gun ownership has gotten much more concentrated among fewer households: if you own one gun, you probably own several. America has the highest rate of gun ownership of any country in the world, by a wide margin (see: international comparison).
The FBI defines a "mass murder" as four or more murders during the same incident. This is an arbitrary number, but a dividing line is useful when asking whether there are differences between mass shootings and other kinds of gun violence. The most comprehensive public list of U.S. mass shootings is the spreadsheet of 62 incidents from 1982-2012, compiled by Mother Jones. Their list shows:
- Mass shootings happen all over the country.
- Killers used a semi-automatic handgun in 75% of incidents, which is about the same percentage as the 72% in overall gun violence.
- Killers used an assault weapon in 40% of incidents. This is much higher than overall assault weapon use in crimes, estimated at less than 2%.
- The guns were obtained legally in 79% of mass shootings.
- Many of the shooters showed signs of mental illness, but in only two cases was there a prior diagnosis.
- There were no cases where an armed civilian fired back.
2012 was the worst year in American history, in terms of total victims. A graph of yearly victims shows a slight upward trend. But the pattern is a lot less clear without the 2012 peak, and because yearly numbers vary so widely, it's likely that there will be many fewer victims next year.
Several criminologists deny that mass shootings are increasing. Although these incidents dominate headlines and conversation, it's important to remember that they account for only a small fraction of gun violence in the United States. For example, the spike of 72 deaths in 2012 includes only 0.8% of all firearm-related homicides in 2011 (the last year for which statistics are available.) Many gun deaths, especially in large cities, never make the news. This means that the most effective gun violence reduction strategies -- in terms of lives saved -- might not target mass shootings at all.
What gun control laws currently exist?
There are two major federal laws that regulate firearm ownership and sales. The National Firearms Act of 1934 restricts civilians from owning automatic weapons, short-barreled shotguns, hand grenades, and other powerful arms. The Gun Control Act of 1968 focuses on commerce. It prohibits mail-order sales of weapons, and requires anyone in the business of selling guns to be federally licensed and keep permanent sales records. It also prohibits knowingly selling a gun to those with prior criminal records, minors, individuals with mental health problems, and a few other categories of people.