Eknoor Kaur, 3, stands with her father Guramril Singh during a candlelight vigil outside Newtown High School before a Dec. 16 interfaith vigil with President Obama in Newtown, Conn. (Jason DeCrow/AP)

Back in the crack-infused 1980s, young men with guns and drugs ruled the single block of Hanover Place NW. People who lived in the two-story rowhouses one mile north of the Capitol fell asleep year round to the sounds of the Fourth of July, a pop-pop-pop that they hoped was firecrackers. It rarely was.

But after two decades of consistent and dramatic declines in homicides and gun violence in Washington and many other major cities, Hanover Place is mostly quiet these days. Complaints to the police tend to be more about kids shooting craps on the sidewalk than about drug dealers shooting at rival street crews. On a block where houses were unloaded for as little as $30,000 in the 1990s, the most recent sales have ranged from $278,000 to $425,000.

As welcome as such changes have been, explanations for the nation’s plummeting homicide rate remain elusive, stymieing economists, criminologists, police, politicians and demographers. Have new police strategies made a difference, or have demographic shifts and population migrations steered the change? Could the reasons be as simple as putting more bad guys behind bars, or does credit go to changes made a generation ago, such as taking the lead out of gasoline or legalizing abortion?

Mass shootings such as last year’s searing incidents in Newtown, Conn., and Aurora, Colo., have put gun and mental-health policies back atop the nation’s agenda. But the narrative of crime over the past two decades runs in a different direction. Law and order has largely vanished as a political issue — in 1994, more than half of Americans called crime the nation’s most important problem; by 2012, only 2 percent of those surveyed by Gallup said so.

Today, there are more theories about why crime has fallen than there were slayings on Hanover Place in the past decade.

(The Washington Post/Source: FBI)

The drop in deaths from firearms and in slayings overall — over the past two decades, homicide declined by 80 percent in the District and overall crime fell by 75 percent in New York City — has come even as the economy has tanked, the number of guns owned by Americans has soared and the number of young people in the prime crime demographic has peaked.

“There has been a real drop in crime, and anyone living in New York or Washington sees it,” said David Greenberg, a New York University sociologist who has tested theories for the decline. “In principle, we should be able to explain it, but it’s easier to determine what factors don’t contribute than it is to say what does.”

On Hanover Place, residents are quick to name two reasons the nights when they heard as many as 75 gunshots are a fading memory: The cast of characters has changed, and the police cleaned out the place.

Starting in the mid-’80s, D.C. police focused on the open-air drug market Hanover Place had become. Emptying onto North Capitol Street, Hanover could not have been better designed for drug dealing and the gun violence it spawns. Entered through a warren of alleys, the street gave bad guys any number of quick exit routes — through back yards, walkways and unmarked alleys — but prevented police in squad cars from seeing anything from adjacent streets.

“It’s not an easy place to get into, even though it’s the perfect walk-in spot for drug sales,” said Andy Solberg, police commander for the 5th District, which includes Hanover Place.

So when the city got serious about taking down dealers such as drug kingpin Cornell Jones, whose family home was on the block, they set up a trailer on a vacant lot and created at least the illusion that the cops were always there, always watching. Then the D.C. government, using federal, local and private money, worked with a community development corporation to buy vacant properties, build houses, and sell them at cost to people with jobs and clean records.

The result is a very different population, said Joyce Robinson-Paul, a 32-year resident and the advisory neighborhood commissioner for the area. “The new neighbors are very quiet,” she said. But “the real crime problem didn’t leave until many of the dealers were arrested and went to jail.”

The Washington Post’s Ed O’Keefe shows us some of the guns targeted by legislation that would outlaw certain rifles, pistols and high-capacity magazines. (The Washington Post)
The explanations

Since Solberg became a police officer 25 years ago, the prison population has tripled nationally, the result of anti-drug and anti-gun enforcement efforts, mandatory minimum sentencing, and the widespread elimination of parole. Most studies agree that increases in incarceration explain part of the decline in violent crime, though Solberg and many criminologists say the warehousing of young men convicted of nonviolent crimes causes as many social problems as it solves.

Police and residents also credit community policing, in which officers meet with local activists and keep close tabs on known bad guys. But studies of police tactics such as New York’s stop-and-frisk campaign or the “broken windows” emphasis on enforcing minor infractions conclude that those measures have little impact on crime.

“In the past, when crime rates went up, police said this was beyond our control, the result of demographic changes,” Greenberg said, “and they were probably right about that. But when crime went down, police took credit for it, and the data just doesn’t support that. The declines were well underway before stop-and-frisk, before ‘broken windows.’ ”

Even increases in officers on the streets showed no correlation with decreased violent crime, he found.

Solberg agrees that police actions alone do not explain falling crime rates. “I’m a cop, so I want to arrest the guys who are committing the crimes,” he said, “but it’s clear that a lot of what’s changed is demographics.”

Population change is no ­slam-dunk explanation, either. Through most of the 1990s, criminologists and politicians, including President Bill Clinton, predicted that crime rates were about to soar, that a generation of super-predators — part of the population bulge created when the baby boomers had children — would reverse the decline in shootings and killings.

It didn’t happen. The number of young people did rise, but crime fell. What did happen in many cities was gentrification. On Han­over Place, some renters had to move when they could no longer afford the soaring price of housing. And some longtime owners cashed out. They moved to Prince George’s County for better schools, safer streets and eye-popping profits, getting $300,000 or $400,000 for houses they had bought for a few thousand dollars.

Jabella Hinton didn’t sell, and this year she celebrates half a century in the home she bought for $7,000 in 1953. “They tried to buy my house, but I ain’t selling nothing,” she said.

She stayed even though in the ’80s “it was really terrible,” Hinton said. “We just had to keep calling the police.” But in the ’90s, “the drug people finally moved on and the police made it better by locking them up.”

Police could not stay on the block forever, so for the change to be lasting, Hanover Place’s crack dens and vacant properties had to go, said Paul McElligott, who headed a redevelopment corporation that acquired more than 20 properties on the street and built new houses.

“The strategy was to focus on homeownership, to get law-abiding citizens who would have a vested interest in the block and look out for each other,” he said.

The original purchasers were working-class families, but over the past two decades, the block’s makeup has become more affluent and more racially and ethnically mixed. Hinton, now 85 and retired, spent her working life checking the quality of paper money at the Bureau of Engraving and Printing. Her new neighbors are lawyers and analysts and computer scientists who work for senators, trade groups and private consultancies.

Policymakers and scholars long assumed that crime and economic health were organically connected — tough times, therefore, should drive up crime. But that didn’t happen after the 2008 financial collapse and the resulting recession.

Property crime does sometimes track the state of the economy, but not always. In the 1960s, despite powerful growth, crime soared. It is clear, however, that violent crime does not correlate with the unemployment rate.

So researchers have looked for other explanations. Steven Levitt, an economist at the University of Chicago, argued that four key factors explain the decline of violent crime: more police, more criminals in prison, the ebbing of crack’s popularity and the legalization of abortion.

Abortion link?

On Hanover Place, men still hang out drinking from bottles in paper bags, but violent crime subsided markedly as the crack cocaine craze of the 1980s faded. Similarly, homicide rates for young black men nationwide spiked as demand for crack expanded, then they fell in the 1990s as crack use declined. (Hospital admissions related to cocaine use fell by two-thirds between 1992 and 2009.)

Levitt’s abortion theory proved more provocative. His data show violent crime dropping two decades after the Supreme Court’s 1973 decision that legalized abortion nationwide. More abortions, he concluded, led to fewer unwanted births and fewer children growing up in situations that would have made them greater crime risks.

Roe v. Wade reduced the nation’s birth rate by about 5 percent, and twice that among teen and nonwhite mothers. Levitt showed that states with the highest abortion rates experienced the sharpest declines in crime; from 1985 to 1997, homicides dropped 26 percent in high-abortion states while increasing 4 percent in low-abortion states.

Some criminologists question Levitt’s narrative and statistical analysis. Killings did drop dramatically in New York City, which had an abortion rate three times the national average, concluded economist Theodore Joyce in a 2009 study for the National Bureau of Economic Research. But the timing and degree of the decline in homicides did not line up with what Levitt’s theory would have predicted.

Other researchers offered a different generational theory — that the decline in crime coincides with the maturation of the first generation raised after lead, which has long been associated with violent behavior, was removed from gasoline, in 1974. Getting the lead out of the air — and out of paint in many homes — resulted in fewer criminals, argued Northern Virginia economist Rick Nevin.

The lead theory has won credence from some criminologists but has not been widely studied, and many scientists are skeptical of any theory that rests largely on finding correlations between crime data and other phenomena.

“It’s non-disprovable, which in the world of science is supposed to mean it’s a non-starter,” said Jack Sava, director of trauma care at MedStar Washington Hospital Center.

Sava is also not certain there is hard evidence to back up the latest medically based theory — that it is not the number of shootings that is declining but rather the number of those gunshot wounds that turn out to be fatal. Non-fatal gun injuries are up slightly over the past three years, according to data from the Centers for Disease Control and Prevention, even as the gun-related homicide rate has hit its lowest point in three decades.

The difference, some researchers say, is improved trauma care rather than any wholesale drop in criminal behavior. Indeed, survival rates are up at many trauma centers, mainly because of new strategies developed in the U.S. military’s battleground operating theaters in Iraq and Afghanistan.

Sava says the average night in the trauma unit is less busy than it was in the 1990s, but he is doubtful that anything hospitals do explains much of the decline in shooting deaths. Locally and nationally, survival rates are up by a few percentage points over the past decade, but that does not come close to accounting for homicide drops such as the District’s 80 percent figure.

Of all the theories surrounding the decline in violent crime, none are more contentious than those involving guns. The National Rifle Association touts numbers correlating the increased number of guns in the country — up from 192 million in 1994 to 310 million in 2009 — with the drop in violent crime. (Of course, on the volatile issue of guns, every fact has an extra nuance. Although the number of guns Americans own is way up, the percentage of people who own those guns is down sharply, from 49 percent of households in 1973 to 32 percent in 2010.)

Economist and gun rights advocate John Lott tracked the increase in concealed-carry permits against crime data and concluded that “allowing citizens to carry concealed handguns reduces violent crimes.” But a National Research Council study found “no link between right-to-carry laws and changes in crime.”

Similarly, although several studies show a statistical relationship between increased gun ownership and high homicide rates, the National Research Council concluded that there’s no proof that more guns result in more violence.

Neither more nor fewer guns seem to result in much change in violent crime. During its three-
decade experiment with the nation’s toughest gun ban, the District experienced both a record-high homicide rate and the sharpest decline in killings of any major U.S. city.

Fear certainly plays a role in shaping attitudes about crime. People who feel threatened are more likely to buy guns. Yet some states that have the strictest gun laws also have the lowest rates of gun-related deaths. And the decline in violent crime has produced a marked drop in fear; almost two-thirds of Americans now say they are not afraid to walk in their neighborhood at night, up from 55 percent two decades ago, according to the University of Chicago’s General Social Survey.

That shift is evident on Han­over Place. New residents still urge police to go after the guys drinking on the corner, but longer-term residents say the block is safer and happier than back when motorists would line up around the corner, waiting to buy $50 and $100 packets of cocaine, back when there were four slayings in one year on the one short block.

“It’s safe now to walk up and down,” said Kelley Powell, 54, who has lived around the corner from Hanover most of his adult life. “The drugs went away, the police came in and the troublemakers went to prison. And people just moved out. Different place now, different place.”