Crime falls, but not everywhere: crime is at historic lows in many places. But school and mall shootings, along with grown-up criminal gangs, are grim reminders that the culture of violence is still with us and on the public agenda.

• Author: Lyons, Donna
• Position: Cover story

The festive surroundings of an Omaha, Neb., department store full of Christmas shoppers quickly turned into the bloody crime scene of a suicidal shooter on a December afternoon in 2007. It was the kind of news that even thousands of miles away makes hearts race, even though recent shootings at Virginia Tech, Northern Illinois University and elsewhere arguably have a numbing effect.

These tragic shootings grab headlines and prompt TV talk show hosts to probe what went wrong in addressing mental health or other disorders of the angry young perpetrators. Meanwhile, some urban communities struggle almost daily with pervasive violence involving drugs, guns and gangs, which often seems unnoticed outside those gritty neighborhoods.

Volatility of crime and violence has the public on guard and law enforcement officials and policymakers exploring issues and approaches. The persistent culture of violence in this country looks different in different places, and prompts any number of crime correlation theories. Indeed, causes of serious crime continue to be complex and pervasive, even at a time when many areas of the country have seen declining rates of crime, including violent offenses.

The FBI's Uniform Crime Reports show the rate of violent crime nationally (that is, crimes per 100,000 population) down dramatically to 473.5 in 2006 from a peak of 758.2 in 1991. And even though the population has grown, the actual number of reported crimes also is down--more than 13 percent between 1997 and 2006.

Rates of property crimes also have declined nationally in the nearly two decades between 1987 and 2006. And the latest Crime in the United States data from the FBI, covering the first half of 2007, show violent crime declining by 1.8 percent and property crime down 2.6 percent in 2007 over the same period in 2006.

Despite the national trends, some cities in recent years have seen serious crime on the upswing. According to Uniform Crime Reports, rates of violent crime varied widely around the country in 2006. The Midwest saw rising crime in 2006, while it declined in the Northeast. Areas of the Midwest and Mountain West also have been hard hit by methamphetamine abuse.

"Crime or the relative absence of crime is very much city-, community- and neighborhood-specific," says Christopher Stone, chair of the Criminal Justice Policy and Management Program at the Kennedy School of Government in Cambridge, Mass. "Different neighborhoods today are having very different experiences."

That dappled pattern means public concern about crime today is equal parts reaction to serious problems in specific places and general edginess created when the culture of violence is seen playing out in random school and mall shootings, says Stone.

Stone says that while people might feel relatively safe in their immediate neighborhood, their fears often reflect what they see happening elsewhere in their city or in the country. Today, the borders of crime and violence are blurry.

"In the 1990s, we had crack cocaine to blame across the board for a lot of serious crime. That's not so today," says Chuck Wexler, executive director of Police Executive Research Foundation, which has studied recent crime trends. "There is no single answer as there seemed to be then."

The police research describes a "tale of two cities," in which "nationwide crime totals mask significantly more serious problems in certain cities or subgroups."

GANG FACTOR

The foundation surveyed law enforcement agencies to try to identify factors contributing to the rising serious crime rates in certain areas. A key concern is gangs and their spread to communities throughout the United States.

"Migration of gangs across the country has brought with it drugs, weapons and other criminal activity," says Wexler. Gangs are the primary distributors of drugs, and gang activity moves into and through more areas of the country today, including small towns and suburbs that may once have felt insulated from it all.

Law enforcement agencies surveyed by the research group also are concerned about juvenile violence with high-caliber weapons, noting that attacks are more deadly when the weaponry is more lethal. Law enforcement...