41% of ’07 killings end in arrest

Times reporters Jill Leovy and Doug Smith crunched the 2007 Los Angeles County homicide numbers to determine how many cases were solved. They posted their findings on The Times’ Homicide Report blog. Here’s the details:

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An arrest was made in about 41% of slayings in Los Angeles County in 2007, according to data collected by the Homicide Report.

The analysis shows that there was virtually no difference in success rates overall between the Los Angeles Police Department and the Los Angeles County Sheriff’s Department.

Although these two agencies -- both among the largest in the country -- follow very different models in investigating homicides, both had arrested suspects in about 40% of all cases by year’s end. The finding suggests that community attitudes and behaviors and prosecutors’ thresholds for filing homicide charges may have more to do with whether killers end up behind bars than any particular law-enforcement model.

The data also showed that clearance rates varied across geographic and demographic lines. The rate of arresting suspects was lowest for cases in which blacks were victims. Countywide, suspects had been arrested in 38% of cases in which blacks were victims, compared with 42% for Latinos and 54% for whites.

All of these findings are preliminary, because an undetermined number of cases will be solved in coming months or years. Many homicide detectives suggest a minimum of two years is needed to fully investigate cases.

In the three highest-homicide precincts of the LAPD, detectives in South Los Angeles arrested suspects in 38% of cases from the first six months of 2007 -- a significantly lower rate than in the county overall. This is consistent with past years’ trends and is a reflection of the greater difficulty of solving cases in high-crime environments, where many people are afraid of testifying against gang members and detectives’ caseloads are higher.

For example, detectives in one of these high-homicide precincts, covering the Exposition Park and Jefferson Park areas, had significantly higher caseloads than detectives in the West Los Angeles and Devonshire divisions. Southwest detectives handled an average of more than 10 cases per detective pair, while West L.A. and Devonshire detectives handled the equivalent of about six cases per pair.

Sheriff’s homicide detectives also carried relatively high caseloads in 2007 -- at least nine homicide cases per detective pair, not including the injury-only police shootings those detectives also investigate.

There are many ways to calculate clearance rates for homicide. While this analysis considers only homicide cases resolved by an arrest, an additional portion of cases involve investigations that are concluded without an arrest.

If these so-called “cleared other” cases are considered along with those resolved by arrests, the countywide rate rises to about 45%.

The majority of “cleared other” cases involved homicides in which prosecutors declined to file charges out of concern that the circumstances of the crime were clouded by self-defense issues.

Although different in methodology, the analysis of 2007 data collected by The Times echoed previous findings on clearance rates.

A 2003 Times analysis of 11,000 homicides in the city of Los Angeles between 1988 and 2002, for example, found that roughly half remained unsolved. A disproportionate number of these cases were in South Los Angeles.

Similarly, an earlier Times analysis of 9,442 homicides committed during the peak homicide years of 1990-94 also found that only about half of the cases had resulted in arrests and charges several years later.

The Homicide Report analysis considered 710 cases in 2007, a portion of the more than 900 killings that occurred countywide. Most, but not all jurisdictions in the county were included in the survey. Murder-suicides and cases in which suspects committed suicide before they could be arrested were eliminated from consideration. Double- and triple-homicides were counted as single cases. Cases in which the suspect remained outstanding on a warrant -- a very small percentage of the total -- were counted as “solved” on the theory that they represented well-advanced investigations. The federal government, however, does not consider such cases as solved or cleared.

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More information: latimes.com/homicidereport or latimes.com/california.