Auto thefts not down as much as reported

A year-end drop in car thefts touted by Los Angeles police was artificially inflated by a statistical gaffe, they acknowledged Tuesday.

At the end of last year, the Los Angeles Police Department touted preliminary numbers showing a roughly 8% drop in “part one” crimes, which include violent offenses and serious property crimes such as grand theft auto.

But department officials confirmed Tuesday that the calculation was slightly distorted by figures derived, not from a change in crime, but from a change in crime classification.

It’s the second time in two years that such a change has contorted reported crime-decrease numbers in Los Angeles. In 2005, a violent-crime drop reported by the department was artificially inflated by a change in the classification of some domestic violence offenses.

In the case of auto theft, before 2006 the LAPD reported overdue rental cars as stolen cars, in violation of federal guidelines, which direct police departments to classify such incidents as fraud or embezzlement. Beginning last year, the LAPD changed its classification to meet the federal standard.

The shift automatically eliminated 488 crimes from the auto theft category, department officials said Tuesday.

If the definitional change is taken into account, the 8% drop in grand theft auto is reduced to about 6%. Car thievery indeed waned, but “the 8% drop is not accurate,” said Mary Grady, department spokeswoman.

The change in auto theft numbers also had a slight impact on the total year-end drop in serious crimes reported by the LAPD. What had been listed as a nearly 8% decline is closer to 7%, authorities acknowledged.

The weaker showing is not entirely due to the auto theft issue. An end-of-year surge in crimes such as homicides, and routine refinement of calculations, also served to slightly reduce the decrease in crime originally promoted in news conferences.

However, classifying overdue rental cars differently had a significant impact on crime statistics reported in certain locales.

Most affected was the Pacific Division, where rental car firms are concentrated because of proximity to Los Angeles International Airport. With the changed categorization, the 30% drop in grand theft auto reported in 2006 in Pacific -- which covers Westchester, Playa del Rey, Mar Vista, Venice and Palms -- shrinks to 4%.

As recently as Friday, spokeswoman Grady had asserted that the 2006 statistics were not affected by the change in auto theft definitions. After further questioning, the department produced accurate information Tuesday.

Grady said the gaffe involved honest mistakes. Noting that statistical reports released by the department always include boilerplate language stating that data is “preliminary ... and may be subject to change,” she denied that the department’s earlier reports were misleading.

The LAPD notified its lower-level supervisors, state officials and the Police Commission of the change in classification early last year. But it did not note on its public releases in any way that the auto theft decrease was artificially inflated.

The department’s handling of the issue contrasted with its approach to the 2005 domestic violence statistical glitch, which produced an artificially large drop in violent crimes.

In that case, although the department continued to use the distorted numbers in its final calculations, it noted by asterisk in public releases that there had been a classification change.

jill.leovy@latimes.com