WASHINGTON - They are here, the mothers say, to save their children from guns.
Gun-rights advocates say they are here to protect their constitutional right to protect themselves.
But beneath the hyperbole surrounding today's Million Mom March, the dueling sets of statistics, and the saturated media coverage of multiple shooting scenes, some basic truths have been obscured, according to academic, government, and police sources.
The gun violence crisis is easing, not worsening. Not all of the gun-control measures being touted on Capitol Hill have been shown to work. Most disturbing, some sociologists say, is that the problem may be much deeper: a culture of violence in the United States, which continues to outpace many industrialized nations in the rate of violent crime.
''The underlying theme of the Million Mom March is `too many guns,''' said David Kopel, a New York University adjunct professor who has written on gun control. ''That's too simplistic.''
While the idea seems to make intuitive sense, Kopel said, merely reducing the overall number of guns in the United States, now at an estimated 250 million, would not reduce crime. And many of the proposals floating around Capitol Hill would not effectively target the problem: the people who use guns illegally, Kopel and others say.
The gun buyback program, a prominent part of the Clinton administration's gun-control campaign, was cited as an example of ''what doesn't work'' in a 1998 report commissioned by the administration's own Justice Department.
Licensing and registering gun buyers also draws skeptics, who argue that the rule wouldn't affect criminals, who presumably wouldn't bother getting legal permission to own a gun. The International Association of Chiefs of Police, which favors certain controls, has taken no position on licensing.
Banning certain kinds of guns has a limited impact, if any, research shows, since criminals would simply use other guns. The 1994 ban on so-called assault weapons had an ''unclear'' effect on gun violence, and did nothing to reduce the average number of murder victims per shooting, according to a report by the Justice Department's Office of Justice Programs.
The most common guns recommended for outright prohibition - assault weapons and ''Saturday Night Specials'' - are in fact used in a small percentage of crimes.
Child safety locks are an appealing thought, gun-control skeptics concede. Even Governor George W. Bush of Texas, the Republican presidential candidate who generally opposes gun control, on Friday offered to give gun locks to owners.
But such locks probably won't save as many lives as advocates suggest. According to an estimate by Gary Kleck, a criminology professor at Florida State University, there are fewer than 100 fatal handgun accidents involving pre-adolescent children each year in the United States.
Moreover, gun locks require the cooperation of the owner. A law requiring gun locks probably would not have prevented a 6-year-old boy in Michigan from shooting his classmate Kayla Rolland, critics say, because the boy picked up the weapon in a home being used as a crack house.
''There's a lot that seems to be done for public relations purposes,'' said Joyce Malcolm, a history professor at Bentley College and author of an upcoming book on gun control in Britain and the United States. ''There's a real temptation to impose laws that aren't going to make any difference. You really kind of misdirect your energies.''
Gun-rights advocates argue that regulations such as mandatory gun locks and waiting periods would hamper their ability to protect themselves. But researchers generally agree that these laws would not prevent a lawful citizen from obtaining a gun.
To gun-control activists, the equation is simple: Fewer guns mean fewer gun deaths. ''We start reducing the number of guns out there, and I am telling you, we are going to save untold numbers of lives,'' said Representative Patrick Kennedy, Democrat of Rhode Island and a leading gun-control advocate in the House.
Legally purchased guns can simply be stolen during a break-in, Kennedy said, giving a proven criminal a weapon.
One idea Kennedy strongly supports is the gun buyback program. But Gretchen Michael, a spokeswoman for the Justice Department, acknowledged that ''there is no empirical evidence'' that gun buyback programs reduce crime.
The programs, in which police offer cash for guns, do not target guns at risk of being used in a crime, said an analysis by Lawrence W. Sherman, a University of Pennsylvania professor who studied the matter for the Justice Department.
Still, the Clinton administration is requesting an additional $15 million in next year's budget for gun buybacks to offer $50 a gun.
Underlying the emotional debate over gun control is the perception that shooting deaths, particularly multiple murders, are increasing. But government statistics indicate the opposite.
Homicides, along with crime in general, are down. Both the murder rate and the number of killings of youngsters younger than 18 have been declining steadily since 1993.
Despite the numbers bandied about by gun-control advocates, the number of youths younger than 18 murdered by any method in 1998 was fewer than 2,000, according to the Bureau of Justice Statistics. The 4,000 to 5,000 youth gun deaths cited by activists often include ''children'' as old as 21, as well as many suicides.
Multiple shootings represent a minuscule part of homicides, and the proportion of murders involving more than two victims has remained virtually the same - less than 1 percent, the Justice Department numbers report.
There is no denying that guns play a big role in murders. The US homicide rate is much higher than in most industrialized nations, and guns are used in about two-thirds of the murders. So what does work to reduce gun violence?
The Brady Law, which requires background checks on potential gun buyers, has stopped 500,000 handgun purchases at licensed dealers, the Justice Department's Michael said. It's impossible to predict whether the denied guns would have been used in crimes, or whether the would-be purchasers acquired guns somewhere else. But those screened out are presumably a higher-risk group, she said.
Programs aimed at collecting illegal guns and prosecuting gun violators more harshly and consistently appear to be working, said Michael and law enforcement groups.
Operation Cease-Fire in Boston and Project Exile in Richmond, Va. - programs that target illegal guns - have decreased gun violence in the two cities, Michael said. Boston has been lauded for its program, which incorporates clergy, community leaders, police, academics, and city officials in a zero-tolerance campaign against youth gun violence.
Richmond's program carries a five-year mandatory sentence for certain gun-possession violations.
The bigger problem, academics say, may be cultural. Rooted in a frontier mentality, Americans behave more violently than people in other countries - even those with far easier access to guns, said New York University's Kopel.
Switzerland, for example, is ''armed to the teeth,'' with virtually every household having at least one gun, even a machine gun, Kopel noted. But homicides are rare there.
And in Britain, often touted as an example of strong gun-control success, homicides and other violent crimes are on the rise, said Malcolm of Bentley College. Manchester, England, is referred to as ''Gunchester.''
''We need to look at a culture of violence, the celebration of `bang-bang, you're dead''' in media and entertainment, said Mary Stange, author of the upcoming book, ''Gun Women: Firearms and Feminism in Contemporary America.''
''To a large extent, there's a sociocultural factor that's driving'' the gun violence, said Bob Cottrell, a constitutional law professor at George Washington University who has written extensively about firearms in America. ''It's not just the sheer availability of guns.''
