Why fewer murder cases get solved

On an autumn Thursday, shortly after 1 p.m., a postal worker in Virginia Beach, Va., found Samuel Baruch on the floor next to the safe in his office. He had been fatally shot during an apparent robbery.

The brazen killing in 1991 was emblematic of a nationwide surge in violent crime that unleashed a wave of campaigns to clean up city streets. But 17 years later, six local homicides from that year, including Mr. Baruch's, remain unsolved.

For decades, the share of homicides that police solve has steadily declined – from over 90 percent in the 1960s to about 65 percent today. The trend defies advances in forensic technology and a federal initiative that has deployed more than 100,000 new cops since the early '90s.

Most surprising, it's persisted even as murders committed in the US have plunged. The national murder rate fell 40 percent between 1991 and 2007, but in a few large cities only about 1 in 3 murders got solved last year. With the economic downturn, expectations are fading that police departments can improve their record by devoting more manpower to tracing killers. Nearly 40 percent of law-enforcement agencies have already cut their budgets, according to a July survey by the Police Executive Research Forum.

"What's going to happen is that you're going to have fewer police trying to solve just as much crime," says criminologist Jay Albanes of Virginia Commonwealth University in Richmond. "If that's the scenario, you can't just continue doing what you're doing now, or you'll continue to slowly slide backwards."

A common explanation for the slide in US closure rates is the gradual but steady shift in the profile of the typical murder. A few decades ago, a majority of homicides involved acquaintances and were not premeditated. Today, most involve strangers and often accompany other criminal activity. Such cases generally present fewer and more-reluctant witnesses.

About three-quarters of murders in Boston are tied to gang members, says Thomas Lee, deputy superintendent of the police department's criminal investigations division and forensics section. That drives down the homicide closure rate, he says, which stood at 36 percent in 2007.

"It's frustrating for us a lot of times," Superintendent Lee says. "Sometimes getting the public on board is our toughest challenge."

Some researchers argue that police work itself is what most influences the closure rate. Boosting the number of homicide detectives assigned to a case from one to four more than tripled the probability of solving it, says Charles Wellford, a University of Maryland criminologist who cowrote a landmark 1999 study on the issue. Decreasing their initial response time also had a large positive effect, he found.

"Only partly is the clearance [rate] driven by the nature of the crime," he says. "If you're looking for reasons [for whether cases get solved], you have to spend some time looking at how police have organized and conducted their investigations."

That view seems consistent with recent results in Boston, where Lee says the addition of seven investigators – even during a budget crunch – helped boost the share of cases solved to 49 percent in 2008 through July. That pattern also played out in Las Vegas, where added manpower pushed the "solved" rate from 54 percent in 2002 to 70 percent in 2007, says Lt. Lew Roberts of the homicide unit.

If cities and counties become more financially strapped, though, infusions of resources are less likely. In Virginia's Fairfax County, hit hard by home foreclosures, the police department has drafted a list of potential cuts worth $27 million, or 15 percent of the budget.

Law enforcement agencies say they intend to preserve the quality of murder investigations. "We will have to curtail some of our services, but solving murders isn't one of them," says Mary Ann Jennings, Fairfax County police spokeswoman.

Very severe cuts, though, could affect even those cases. No. 26 of 34 on the department's list of potential money-savers: axing the cold case squad, which investigates old killings and sexual assaults. From 2002 to 2007, Fairfax County solved 85 percent of its murders, far above the national average. Eliminating cold-case investigators not only would diminish the likelihood of solving old cases, but it also would require detectives working fresh cases to take on additional duties. "Homicide and sexual-assault closure rates would decrease due to longer response times required for investigations," according to the department.

In Sacramento, Calif., with 12.5 percent fewer officers than a year ago and a police budget 8 percent smaller than last fiscal year, officials hope that staff cuts will stop at divisions dealing with nonviolent crime. But the poor economy might eventually force the issue. "I don't think anything's off limits," says Sgt. Norm Leong.

With leaner staffs and budgets, police departments are likely to look for low-cost ways to maximize efficiency. Some agencies post consistently high closure rates for murder cases because of the way they organize their forces, says Dr. Wellford.

Police in San Jose, Calif., have solved about 87 percent of murders over the past decade, says Lt. JR Gamez, who heads the homicide unit. The department's rotation policy underlies much of its success, he says. After five years in the unit, detectives must spend a year patrolling the streets before reapplying, so seasoned investigators often become first responders.

"They know what they need to do in a preliminary homicide investigation," he says. "By the time the homicide detectives get there, everything is kind of in a nice little package."

Programs and services with indirect effects on murder clearances are also at risk of being scaled back. On Fairfax County's list of proposed cuts, for instance, is language training and neighborhood watch instruction, which the department says would impair its ability to communicate with Hispanic communities. Crime labs may also see thinned budgets.

But David Ramirez, executive assistant to the San Diego, Calif., chief of police, doubts that budget cuts will erode murder-case closures. "We should be fine for the next year or two," he says. "I want to try to remain somewhat optimistic."