From here, the Long FAQ on Liberalism.:
Myth: Gun control laws won't reduce the gun homicide rate.
Fact: The murder rate almost always falls after the enforcement of gun control laws.
There are numerous examples of gun control laws that have reduced the murder rate -- both domestically and internationally.
Contrary to what the gun lobby would have you believe, there is abundant evidence that enforcing gun control laws reduces the gun homicide rate.
One of the most remarkable examples was a 1992-93 Kansas City experiment by the National Institute of Justice. There, police officers in a large section of the inner city agreed to work overtime to remove illegal guns from the streets. During these overtime shifts, they were given no other responsibilities but to search for and confiscate illegal weapons. This heightened enforcement (of existing gun laws) lasted 29 weeks. The study compared the crime rate during this period to the prior 29 weeks; it also compared the "target area" with a "comparison area" which experienced no changes in its normal police duties. The population of the target area was almost entirely nonwhite and had a crime rate 20 times the national average.
The results were dramatic. Seizures of illegal guns in the target area climbed 65 percent above normal, while they actually declined somewhat in the comparison area. Meanwhile, gun crimes declined 49 percent in the target area. Drive-by shootings fell from 7 to 1 in the time periods compared. The rates for other types of crime did not change, but -- most significantly -- there appeared to be no spillover of crime from the target area into surrounding areas. (For more details of this study, see Appendix A below.)
There are other examples of stricter gun control passing into law, their success depending on how fully they were enforced:
An interstate comparison of the United States is also quite revealing. All states, some localities, and the federal government have laws concerning weapons, including their sale, possession, manufacturing, importation and use. Examples include bans on machine guns, carrying concealed weapons or sales to felons. Violations of these laws are called "weapons offenses," and they make up about 2 percent of all arrests nationwide. They do not include crimes like armed robbery, armed assault, etc.
- The Massachusetts 1974 Bartley-Fox Amendment, which prescribed a 1-year sentence for unlicensed public carrying of firearms, decreased gun assaults, gun robberies, and gun homicides during the 2-year period in which it was evaluated. (1)
- Several State mandatory add-ons to felony sentences for use of a gun have reduced gun homicides, but whether they have discouraged gun use in robberies and assaults is not clear. (2)
- The decrease of gun homicides in Washington D.C. following passage of the 1976 D.C. Firearms Control Act appears to have been maintained until the mid-1980's when, according to a recent study, the rise of crack markets was accompanied by a substantial increase in gun homicides. (For more details, see Appendix B below.) (3)
- The 1968 Federal Gun Control Act, which prohibited Federally licensed gun dealers from selling guns to certain designated "dangerous" categories of people, failed to reduce firearm injuries or deaths, apparently because of lax enforcement. (4)
- The Brady Law, which requires a background check on gun-buyers to screen out criminals, went into effect nationwide in 1994. It prevented 40,000 felons from buying guns in that year alone, and saw a 3.56 percent drop in handgun homocides, a 3.16 percent drop in aggravated assaults and robberies, and a 6.84 percent drop in the number of those crimes committed with a firearm. (5)
- Both the general homicide and gun-homicide rate declined in Canada after 1978, which may have been due to the passage of C-51, a law which considerably tightened restrictions on guns. (See Appendix C below.)
- And of course there is Europe, which has far stricter gun control laws than the U.S., and a far lower murder rate as well.
It turns out there is a quite strong correlation between the murder rate and the weapons offense arrest rate.
State murder rates (per 100,000 population) and weapons offense arrest rates (per 100,000 population), 1993. (t = tie) (6) Weapons Weapons Murder Offense Murder Offense State Rate Rate Rank Rank ------------------------------------------------ Louisiana 20.3 142 1 4 Mississippi 13.5 135 2 8 New York 13.3 102 3 20 California 13.1 135 4 9 Maryland 12.7 104 5 19 Texas 11.9 139 6 7 Alabama 11.6 67 7 34 Georgia 11.4 149 8 3 Illinois 11.4 75 9 30(t) North Carolina 11.3 132 10 10 Missouri 11.3 199 11 1 Nevada 10.4 141 12 5 South Carolina 10.3 77 13 29 Arkansas 10.2 126 14 13 Tennessee 10.2 131 15 11 Michigan 9.8 107 16 16(t) Alaska 9.0 107 17 16(t) Florida 8.9 68 18 33 Arizona 8.6 114 19 15 Oklahoma 8.4 91 20 24 Virginia 8.3 129 21 12 New Mexico 8.0 71 22 32 Indiana 7.5 59 23 38 West Virginia 6.9 77 24 28 Pennsylvania 6.8 49 25 40 Kentucky 6.6 106 26 18 Kansas 6.4 94 27 22(t) Connecticut 6.3 116 28 14 Ohio 6.0 97 29 21 Colorado 5.8 140 30 6 New Jersey 5.3 94 31 22(t) Washington 5.2 75 32 30(t) Delaware 5.0 30 33 44(t) Oregon 4.6 81 34 26 Wisconsin 4.4 165 35 2 Massachusetts 3.9 35 36 42 Nebraska 3.9 78 37 27 Rhode Island 3.9 60 38 36(t) Hawaii 3.8 60 39 36(t) Vermont 3.6 1 40 50 Wyoming 3.4 31 41 43 Minnesota 3.4 61 42 35 South Dakota 3.4 41 43 41 Utah 3.1 85 44 25 Montana 3.0 12 45 49 Idaho 2.9 52 46 39 Iowa 2.3 30 47 44(t) New Hampshire 2.0 16 48 48 North Dakota 1.7 25 49 46 Maine 1.6 23 50 47 -------------------------------------------------- Correlation .67 .71 to crime (7)The correlation between crime and weapons offense arrests is .67 for the raw statistics and .71 for the state rankings. These are both quite strong and highly significant correlations.
Of course, there is an obvious criticism to the above chart. It could simply prove that murderers have a penchant for handling their weapons illegally -- something we already knew.
However, this chart also shows that there is value to gun control laws, since the behavior and weaponry they regulate are correlated with higher murder rates. It also suggests that enforcing these laws more strictly would reduce the murder rate.
To see why, consider drunk driving laws. It doesn't matter whether drunk driving is legal or not - it is the behavior itself which is correlated with higher traffic fatalities. At first the U.S. did not regulate drunk drivers, and the result was a tragically high fatality rate. But eventually the nation passed DUI laws, and each time it has strengthened them, traffic fatalities have fallen. If we were to compare the states' statistics on DUI arrests and traffic fatalities, we would expect to find the states with the most DUI's experiencing the most fatalities. This would call for stricter passage and enforcement of DUI laws.
(As an aside, it would be illogical for a drunk driving lobby to argue that they have the right to drive drunk as long as they don't hurt anyone. We would surely think it strange for them to argue that police should crack down only on the drunk drivers who cause accidents, and that "law-abiding" drunk drivers should not be "persecuted" with DUI convictions.)
Of course, the opposite argument is also possible: more arrests could be a symptom of greater commitment to law enforcement. In that case, the higher fatality rate is occurring in spite of, not because of, greater law enforcement efforts.
To disprove this reverse causal arrow, a few preliminary observations are necessary. First, law enforcement can be divided into two categories: effective and antagonistic. Banning free speech would be an example of antagonistic law enforcement; the more a state tried to enforce it, the more people would rebel against it. That's only to a certain point, however; when Gestapo-like enforcement becomes too brutal, people eventually comply. Compare this to effective law enforcement -- for example, writing tickets for speeders. If the speed limit is 50, but everyone is driving 70, the police face a massive crackdown job. They are going to have to work overtime writing tickets until finally a reputation is established, and drivers learn to slow down. But once everyone is driving 50 again, then law enforcement can be reduced; only a fraction of the police are necessary to catch the occasional speeder. Notice that in the compliance phase of antagonistic enforcement, lots of police are necessary; in the compliance phase of effective enforcement, few police are necessary.
What defines the difference between effective and antagonistic law enforcement? It ultimately boils down to people's attitudes towards a specific law. People believe that free speech is a cherished right, but they do not believe the same thing about the ability to drive 70 miles an hour. Indeed, most people can see the need for lower speed limits, especially in crowded cities.
Now, a gun advocate may claim that gun control laws are antagonistic, and the reason why more weapons arrests are tied to higher murder rates is because we are still in the rebellious stage, not the police state/compliance stage. However, murder is not free speech; people do not have a right to commit murder, much less be antagonized by its unlawfulness. Furthermore, murder does not fit the definition of an antagonistic law; almost everyone sees the need to curtail it, and therefore agrees with it.
That, gun control advocates claim, would make gun control laws effective law enforcement. And the experiences of Kansas City, Washington D.C. and Europe show that gun control laws do not result in rebellion, but lower murder rates. Most of the nation, however, is still in the pre-crackdown phase, much like the stage where most drivers are breaking the speed limit or driving drunk. The states with the most egregious violators are making the most arrests, but no states are seriously cracking down on weapons offenses.
It is more reasonable to conclude that enforcing gun control laws will reduce behavior that is tied to higher murder rates.