Reliability of Crime Statistics in Doubt

September 20, 1990

Your article, "Pasadena, Pomona Mark Dip in Crime," (Times, Sept. 13) would be soothing if the statistics reflected fact, which I doubt.

In your Aug. 9 edition of the San Gabriel Valley section, you published another article, "Major Crime Up 9.8%, FBI Says." Two figures of particular interest to me as a Pomona resident leaped out of the table accompanying the article. One says Pomona's total crimes in 1989 increased 2.2% over the total for 1988. According to this, Pomona ranked 20th out of 25 San Gabriel Valley cities who averaged an increase in crime of 9.8%. That is good. It appears Pomona is doing something right compared to its neighbors.

However, Pomona is shown to have a rate of 81 crimes per 1,000 residents, compared to an average of 60 per 1,000 for the whole valley. That's not good.

I attempted to glean more from the table and was successful in learning the figures don't add up to make sense. As an example, the actual total across the table for the entire valley is 61,477, not the 75,121 in the last line of the table. This is a difference of 13,644 crimes.

Reading the article, I learned some crimes are not included in the details of the table. Arson, for example. Further reading discloses Pomona reported 421 arson crimes, almost three times as many as West Covina's 151, the next highest. And it turns out Pomona includes trash, dumpster and minor brush fires in its arson category. The implication is other cities do not. According to the article, when Pomona uses the same criteria as other cities, its 421 reduces to 75 structure and 56 vehicle fires, a total of 131! If we allow Pomona to deduct the difference from its 1989 total, we arrive at 9,763 total crimes, which is a decrease of 1% from 1988!

Conclusion: There is no way one city's experience with crime can be compared with the whole of the valley or another city's.

Conclusion: Trivial readjustments of the classification rules can materially alter a community's image.

Conclusion: The dip during the first half of 1990 noted by the attorney general of California could be a result of readjusting the rules of classification.

In May of this year, my daughter and granddaughter were pursued by two men in a car through Ganesha Park in Pomona. As she drove from the park, two shots were fired by the occupants of the other car. She drove immediately to the Pomona police station, where an hour elapsed before she could see an officer. No report was made of the incident.

My overall conclusion is that crime reporting and analysis are unreliable and probably highly sensitive to financial and political pressures.

I recommend The Times view with skepticism the content of the statistics reported by law-enforcement agencies and caution its readers about drawing inferences from their analyses.



Los Angeles Times Articles