Ask homicide detectives what the No. 1 roadblock to their investigations is, and, by far, the leading response is "witness cooperation." That's one reason the average homicide clearance rate — cases solved by police departments compared with the number of known homicides — which approached 90 percent in 1960 is now a third less, 61 percent.
It's one of the significant findings in "An Exploratory Analysis of Factors Affecting Homicide Investigations," a study by three FBI researchers that appeared in the February issue of Homicide Studies. The study used data from 55 big city police departments and set out to examine law enforcement practices in a number of areas, including investigative procedures, analytical methods and demographics of the population served. The researchers hoped this would help them come up with some conclusions as to why homicide cases are becoming tougher to close.
Although well researched, some of the study's findings seem obvious, the kind of information that can be gleaned from watching almost any episode of Law and Order or CSI. For example, formal training of homicide detectives and the use of sophisticated investigative techniques such as blood spatter analysis increase closure rates. The study also notes that some crime scenes are so compromised in an evidentiary sense that the murders might never be solved.
Another finding of note is that, not surprisingly, media coverage can be a double-edged sword. It can focus attention on a particular case but also flood local police departments with so many phone calls regarding alleged leads that legitimate leads prove harder to find and pursue.
And, according to the study, interdepartmental cooperation, say between detectives and prosecutors, should make investigations more effective, but, says one of the study's co-authors, John P. Jarvis of the bureau's Behavioral Science Unit, "The issue might be that the cooperation might be viewed by the public as 'we're all in this together'" — a positive in some eyes but an improper collusion in others. "It's counterintuitive, but that's our interpretation of the data."
"Prosecutors have a very different job, and we're both looking to get a conviction," adds study co-author Timothy G. Keel, of the FBI's National Center for the Analysis of Violent Crime. "They have different requirements of what they need to bring a case to court, and that might bring conflicts."
All of this, valuable as it is, still does not totally explain the discrepancy in closure rates between now and 50 years ago. But Jarvis might be on the right track when he notes that "some have said there was not the proliferation of drugs, weapons or gang activities then as there is now."
In fact, the authors argue that the proliferation of drugs and gangs in certain areas has turned the conventional wisdom on its head. Rather than a police tendency to devalue victims from minority communities, hence ignoring or failing to pursue homicide investigations in these areas, it is actually "police devaluation" that is at the root of the problem.
"A victim or a person who knows them might distrust the police," Jarvis says, "but you also have victims who might not want to go to the police. They don't believe the police are the tool or the mechanism for resolving that behavior."
"It's not fear of the police," Keel claims, "it's fear that if they cooperate, there will be retaliation from individual criminals." Jarvis and Keel point to two factors: the retaliatory nature of gang behavior and the "don't snitch" mentality.
"They don't go to the police if someone is killed," Jarvis says of the gangs. "They say, 'We'll kill two of yours.'" He adds that victims and witnesses sometimes refuse cooperation with law enforcement agencies, either because those agencies are viewed as corrupt and racist or because cooperation can lead to violent retribution by criminals.
"The parties involved in a lethal conflict that results in a homicide may not only view the police with mistrust," according to the study, "but may also view the conflict as one in which informal street justice may be a more effective resolution for the parties involved than the formal social control that the police represent."
The solution to this problem, according to the study, is simple but not easily achievable: "There has to be a relationship between the police and the community that has to be one of faith in each," Jarvis says. He points in particular to Operation Ceasefire, a 1996 Boston initiative aimed at curbing youth and gang violence. The essence of the program was that law enforcement agencies told gangs there would be swift and sure consequences for violence, and because these agencies kept their word, two years after the program was implemented, gun assaults and homicides by persons under the age of 24 had decreased by more than 70 percent.
"It's more than tough love," Jarvis says of programs like Operation Ceasefire. "It's opening lines of communication and a partnership."
But, Keel adds, "The reality is that when they live with gangs and that is the culture there, it's difficult for a community to get control of that situation when they lose control."
Still, not all homicides are drug- or gang-related. And even though, according to Jarvis, "there's a public expectation that every homicide will be solved, that's not true. There will be some cases where there are no viable leads, no physical evidence, no witnesses. Should it be 30 percent or 40 percent of the cases? No."
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