We have over 20,000 gun control laws in this country, with more being proposed all the time. We also have had a declining rate of violent crime for the past two decades. You may think that these two are related but as I will try to prove there seems to be a negative correlation between the two, meaning that more laws do not mean less crime. The areas with the most restrictive gun laws seem to have the highest rates of overall crime crime, while the areas with the least restrictive laws enjoy a lower rate of overall crime.
Lets start with the city that seems to lead the nation in number of murders, Chicago, IL. In Chicago it is virtually impossible to get permission to own a handgun. This will be changing as they have been told by the Supreme Court, in McDonald V. Chicago, that it is unconstitutional to deny the Second amendment right that the rest of the country enjoys. It is also impossible, for the time being, to carry a handgun anywhere in the state of Illinois. This will be changing as the state has been ordered to enact some form of carry as a result of the Shepard V. Madigan court case, which overturned the total ban on carrying a firearm outside of ones home. With these two restriction still in place there were over 500 murders in Chicago last year, and they are on a pace to beat that this year with 42 in January alone (just extrapolating that number gets them to almost 500, and violence tends to increase as the weather gets warmer). This in a city where the law abiding are prohibited from defending themselves outside of their homes and discouraged, via strict regulations, from doing so inside of their homes.
Or perhaps you would prefer to look at the most violent city in the US, Detroit, MI. They are at or near the top in every category of crime per the FBI statistics. 2137 violent crimes per 100,000 people, 48 murders, 60 rapes, 695 robberies, 1333 aggravated assaults. This city had, until 2001, strict licensing of handgun ownership, a habit that takes time for the people to break.
We can now move on to some place with much less restrictive gun laws, like Manchester, NH. In Manchester, indeed in all of New Hampshire, one can carry a firearm openly without getting permission from the government to do so. If you would like to carry a concealed weapon it will be issued as long as you are no prohibited from owning a firearm (basically, the chief of police in your town needs to prove you shouldn't have it), and costs a whopping $10 - for FOUR years- for a resident. The latest stats from the Manchester Police Department, for 2010, lists 2 murders, 63 rapes, 154 robberies and 290 aggravated assaults. Since the population is about 100,000 those can be taken as the rates per 100,000. These numbers are all down from the 2009 numbers as well.
In every city or state where the have loosened restriction, crime rates plummet. When Florida went to a shall issue permit law, the left predicted blood in the streets, shootouts over fender benders and general mayhem from gun owners. What happened there, and in every other place that has followed suit, is that crime dropped in every category, and in every segment of the population save one. At the time Florida issued distinctive plates for rental cars, making them easy to identify. The only segment of the population that didn't enjoy the same drop in crime was, you guessed it, tourists, as the criminals could be reasonably sure their targets would be unarmed if they were driving a rental car. A few years later Florida started issuing the same series plate to rentals as to the general population and the crime rate against tourists dropped to almost the same level as the rest of the population (some criminals work near the airports and attractions).
Law abiding citizens who get government permission to carry a firearm (which shouldn't be necessary but we'll get to that later) are not the problem with crime in this country. The biggest problem is criminals that aren't punished severely early in their career, with the police and courts playing catch and release while the criminals get taught that there are no repercussions for their actions. Another problem is the (lack of a) mental health system in this country, which allows those like the maniacs who have been committing the recent shootings to fall through the cracks. Most of them exhibited signs on mental instability in school, but as soon as they were removed from the school no one cared enough to keep track of them or report them to authorities who might of been able to enter them into the NICS database, allowing most of them to buy firearms legally. Leave the law abiding alone to be able to protect themselves and punish those who break the laws.