As the Senate considers new gun control measures, it may be useful to examine the regulations in place in other countries around the world.
The United States has one of the highest rates of gun violence in the developed world, as well as one of the highest gun ownership rates. There is much less gun violence in total, and much less per capita, in countries with similar standards of living and levels of prosperity, like the United Kingdom, Japan and Australia.
Those countries have strict gun ownership laws and low rates of gun ownership. However, rates of violence in general, and particularly the mass killings that so enthrall and frighten the American public, are lower in those countries than in the United States.
Canada, in contrast, has strict ownership laws but high rates of ownership, yet our northern neighbor has rates of gun violence similar to the other countries listed. A specific common denominator is hard to pinpoint, but experts have pored over the numbers for years.
Those numbers are often in dispute. The United States does not require gun registrations and keeps no comprehensive list of gun owners or their firearms, so there is no way to know exactly how many guns are in the country. A typical estimate is around 300 million guns, about one for every man and woman in the country, as well as most of the children.
Surveys, which are admittedly incomplete, show that between 35 and 50 percent of American household have at least on gun, with the vast majority of the guns in the country concentrated in the hands of a relatively small group.
In 2010, over 11,000 people in the United States were killed with a firearm, about 1 out of every 33,000 people in the country.
United Kingdom
In contrast, gun murder rates in the U.K. are 40 times lower, about 1 in every 1.5 million people. The U.K. has enacted many of the gun control regulations advocates have been lobbying for in the United States.
Automatic and semi-automatic weapons are banned, a proposal dubbed the "assault weapons ban" in the United States, and one that was recently dropped from the Senate bill for lack of support from either party.
Snub-nose weapons are also banned, and only shotguns and manually-loaded pistols and rifles may be owned by the public. Guns of this type are essentially single-shot, meaning they must be reloaded after each time they are fired, making them difficult to use in mass shootings.
In the U.S., a ban on high-capacity magazines, which would have limited guns to 10 shots in a row before reloading, was dropped. No limit exists except for practicality, and many guns have magazines that hold 30 bullets or more.
The U.K. also requires firearms owners to have a good reason for owning a weapon, and must pass background checks, a safety course, and must receive a registration that must be renewed every five years, just like a driver's license in the United States.
Criminal convictions result in a five-year suspension of a registration, and long-term prison sentences result in lifetime bans.
Australia
Australia has a slightly higher gun murder rate than the United Kingdom -- 1 in 750,000 people -- but its gun control laws are more relaxed, though not by much.
After a mass shootings that killed 35 people in 1996, Australia enacted many of the restrictions used in the U.K. and proposed in the United States. Despite its relatively high gun ownership rate, violence plummeted, and the government instituted a gun buyback program.
Semi-automatic handguns, which can fire multiple shots in a row but only fire a single shot each time the trigger is pulled, are not banned however, as they are in the U.K.
Japan
Japan has extremely strict gun regulations, but it also has extremely low rates of gun murder. In 2008, 1 out of every 11 million people in Japan were killed by handguns.
All guns are banned in Japan except for hunting rifles and shotguns. The police do not carry guns.
In order to obtain even a hunting rifle or a shotgun, Japanese citizens must take written and practice tests, then submit to an exhaustive background check usually reserved in the United States for people applying for government work.
The applicant must have their mental health certified, and then the gun and ammunition must be stored in separate locked locations, and the whereabouts filed with police.
There are annual inspections, and the process must be repeated every three years.
Canada
Canada isn't as safe as Japan, but its gun murder rate is relatively high compared the other countries on this list, though it is much lower than the rate in the United States -- about 1 in 100,000 people.
Automatic weapons are banned, as are most semi-automatics and snub-nosed and modded weapons. Gun owners must pass background checks and take safety courses, and there is a 60 day waiting period before a purchase can be made.
Checks are also mandated in private sales. The Senate bill includes a provision to require checks in private sales in the United States, and the "gun show loophole" is a popular target to close among Americans of all political persuasions, including gun owners.
In the developed world, it is clear that the amount of gun regulation is directly proportional to the amount of gun violence. Much of the gun violence in the United States can likely be attributed to lax gun regulation in the country.
Though many factors affect violence and murder, it is easier to obtain, keep and use a gun in the United States than in nearly any other developed nation in the world.