Minnesota DFLers think they have found Republican gubernatorial candidate Norm Coleman's Achilles heel. So what is Coleman's supposed weakness? At least until last week, when he appeared to soften his position, Coleman supported replacing Minnesota's current subjective discretionary concealed handgun law with objective standards regarding training and criminal background checks to determine who is granted a permit.

Ted Mondale claims that Coleman "threatens the safety and security of our families." Mike Freeman says it will lead to "impulsive gun violence." DFL radio ads assert that Coleman is putting "our children at risk." Among DFL gubernatorial candidates, only Doug Johnson supported Coleman's position.

Given the horrific crimes committed with guns, such opposition is understandable. But much of the public policy debate on guns is driven by lopsided news coverage that mentions only the crimes committed with guns. Usually ignored are the over 2 million times each year that Americans use guns defensively. Dramatic stories of mothers who use guns to stop carjackers from kidnapping their children seldom even make the local news.

Police play an extremely important role in reducing crime, though they virtually always arrive at the crime scene after the crime has been committed. The question is what would-be victims should do when they must face a criminal by themselves. Passive behavior, particularly for women, is not the wisest course of action. The probability of serious injury from a criminal confrontation is 2.5 times greater for women offering no resistance than for women resisting with a gun. Allowing people to defend themselves also deters criminals from attacking in the first place.

Guns enable "bad guys" to kill more easily, but they also allow the innocent to defend themselves. The crucial question becomes: What is the net effect? Do guns deter crime or encourage it? Are more lives saved or lost? Anecdotal evidence cannot resolve this debate.

To provide a more systematic answer, I published a book on gun control that analyzed FBI crime statistics for all 3,054 American counties from 1977 to 1994 as well as extensive information on accidental gun deaths and suicides. The study examined states that changed from discretionary to objective concealed-handgun laws. Thirty-one states now have these "right-to-carry" rules.

The findings were dramatic. The more people who obtain permits over time, the more violent crime rates decline. After concealed handgun laws have been in effect for five years, murders declined by at least 15 percent, rapes by 9 percent and robberies by 11 percent. These are the drops over and above the recent national declines and after such things as changing arrest and conviction rates, demographics, and other gun-control laws have been accounted for. The reductions in violent crime are greatest in the most crime-prone, most urban areas. Women and blacks gained by far the most from this ability to protect themselves.

The benefits of concealed handguns are not limited to those who carry them or use them in self-defense. That these weapons are concealed keeps criminals uncertain as to whether potential victims will be able to defend themselves with lethal force.

What about the concern in DFL's ad about "allowing virtually anyone to carry a concealed gun"? The evidence in other states indicates that those willing to go through the permit process are extremely law-abiding. Permits are revoked for any reason very rarely, and most of these revocations have nothing to do with improper use of a firearm.

Concerns that permit holders would shoot others after traffic accidents or angry-drivers-cut-off-in-traffic shootings have proven unfounded. Despite millions of people now holding permits and some states having issued permits for as long as 60 years, only one permit holder has ever used a concealed handgun after a traffic accident, and that case involved self-defense.

No permit holders have ever shot at, let alone killed, a police officer; instead, permit holders have on occasion saved the lives of police officers who were being attacked by criminals. I found no evidence that concealed handgun laws caused either accidental gun deaths or suicides to increase.

A system of objective standards also has an important advantage over discretionary rules that let public officials decide on a case-by-case basis who deserves a permit. Discretionary rules have made it especially difficult for the poor and minorities, who are not as well connected politically but who face the greatest threats from crime, to get permits.

Surely one of the most terrifying incidents anyone can witness involves the shootings of multiple victims in a public place. Victims recount their feelings of utter helplessness as a gunman methodically shoots his cowering prey. Some countries have reacted to these events by banning guns, though others, such as Israel, have taken to licensing their citizens to carry concealed handguns. Indeed, much of the impetus for concealed-handgun laws in the United States during the 1980s arose from the belief that these laws would prevent such attacks.

Using data on these shootings for all states from 1977 to 1995, incidents in which at least two people were killed or injured in a public place were also studied. Shootings that were the byproduct of another crime, such as robbery, were excluded. The United States averaged 21 such shootings per year, with an average of 1.8 people killed and 2.7 wounded in each one.

A range of different gun laws as well as other methods of deterrence, such as the death penalty, were examined. However, only the concealed-handgun laws succeeded in reducing deaths and injuries from these shootings. When states passed them, the number of multiple-victim public shootings declined by 84 percent. Deaths from these shootings plummeted by 90 percent, injuries by 82 percent. Shootings still occur in places like schools, were guns are illegal. Higher arrest rates and increased use of the death penalty slightly reduced the incidence of these events, but the effects were never statistically significant.

While national surveys of police show they support concealed handgun laws by a 3-1 margin, the experience after passage of concealed-handgun laws has caused even former opponents in law enforcement to change their positions. A typical response was provided in December by Glenn White, president of the Dallas Police Association. He said, "I lobbied against the law in 1993 and 1995 because I thought it would lead to wholesale armed conflict. That hasn't happened. All the horror stories I thought would come to pass didn't happen . . . I think it's worked out well, and that says good things about the citizens who have permits. I'm a convert."

To date, I have made my data available to academics at 36 universities. Everyone who has tried has been able to replicate my findings, and only three have written pieces critical of my general approach. Although the vast majority of researchers concur that concealed-handgun laws significantly deter crime, not even these three critics have argued that allowing concealed-handgun laws increases crime.

Before my work, the largest previous study examined 170 cities within one single year and found results similar to my own. Ted Mondale frequently cites the only study that has found any category of crime to increase. Yet that study picked a total of only five counties from three states, with no explanation on how those five counties were chosen, and accounted for no other factors that affect crime.

Both sides in the gun control debate have their own anecdotal stories, and surely many hypothetical horror stories will be raised before this campaign is through. Fortunately these fears are easily disproved once one looks at the experience in other states. The benefits are also equally obvious. My estimates for Minnesota, based upon its characteristics, indicate that a right-to-carry law would prevent about 1,500 violent crimes each year.