As the nation remains locked in a bitter debate over reducing gun violence, two new studies released Tuesday found that shooting deaths and other gun crimes have already plunged since peaking in the 1990s. There were 18,253 gun-related killings in 1993, and 11,101 in 2011, the federal Bureau of Justice Statistics reported. With population growth, that meant that the rate of gun homicides dropped by nearly 50 percent — from seven per 100,000 people in 1993 to 3.6 per 100,000 in 2010, Pew Research Center reported. And non-fatal gun crimes dropped even more sharply, by 69 percent.

Here's the twist: Only 12 percent of Americans said they thought there was less gun crime than two decades ago, according to a Pew survey. Twenty-six percent said the rate hadn't changed, and 56 percent said it had gone up. Women, people of color, and the elderly were particularly likely to believe gun crime was rising. "It's hard to know what's going on there," says D'Vera Cohn, senior writer at the Pew Research Center. Why the disconnect between perceptions of violence and reality? Three theories:

Conservatives, who oppose Democrats pushing for tougher gun laws, blamed the misperceptions on what Allahpundit at Hot Air called the pro-gun-control "propaganda machine." President Obama and allies in the media, Allahpundit says, pointed to the December massacre at Sandy Hook Elementary School "to push their broader gun-control agenda even though the measures they proposed would have done zip to stop Adam Lanza." The most recent figures show that fewer than 2 percent of inmates got their guns at flea markets or gun shows. Remember that the next time Obama and Biden are "wheezing about the gun-show loophole," says Allahpundit:

If you're a low-information voter watching Obama's various pressers over the last five months, why wouldn't you assume that gun crime is spiraling ever upward? Rhetorically, at least, [Obama has] spent more time on gun control than he has on any other issue — more than unemployment, North Korea and Syria, immigration, you name it. The problem must be getting worse to justify making it his tippy top public priority; otherwise, one might be forced to conclude that he's demagoging it simply as a handy bludgeon to try to use against the GOP in the midterms. And that can't be true. Can it? [Hot Air]

Some observers, however, blame the disparity between perception and reality on the "if it bleeds, it leads" theory of journalism. "Mass shootings like those in Aurora, Colo., and Newtown, Conn., resulted in round-the-clock coverage by the news media that lasted for days on end," says Doug Mataconis at Outside the Beltway. Local news stations are particularly susceptible to the ratings-boosting allure of sensationalism coverage of violence. Newspapers have delayed deadlines and more time for thoughtful analysis, so they're not quite as obsessed, but they're certainly not immune, he adds:

The result, arguably, is that this coverage creates the impression in the minds of the public that we live in a far more violent society than we actually do. In reality, the odds that the average citizen will be the victim of a violent crime, and specifically a crime involving a gun, is far lower than it was 20 years ago. But, you wouldn't know that by watching the media. [Outside the Beltway]

The third theory is that people aren't noticing a drop in gun crimes because there really hasn't been much change lately. "Virtually all of the decline in gun homicides took place during the 1990s," says Brad Plumer at The Washington Post. The decline halted in 2001, then started again in 2007, but more slowly. The same was true for other crimes in which firearms were involved, including assaults, robberies, and sex crimes. In the early '90s, Mother Jones recently noted, "crack markets withered," and a vibrant economy was steering low-skilled young people into jobs, and away from crime. That's all ancient history now, though, which might explain why so many people have forgotten how bad things used to be.