BALTIMORE(AP)- Several criminologists are expressing doubt about crime statistics that Baltimore Mayor Martin O'Malley uses to claim large reductions in violent crime.O'Malley, who is running for governor, routinely claims violent crime in Baltimore has declined nearly 40 percent since he took office in December 1999. He says the progress outpaces every other big city in the nation.But several criminologists told The (Baltimore) Sun that O'Malley's "nearly 40 percent" claim is an inflated assessment.The criminologists point to an O'Malley-commissioned audit in 2000 that found violent crime had been under-reported in 1999. The audit led to an upward revision of city's violent crime rate for 1999, the year the mayor was elected. That is the benchmark against which O'Malley measures progress.Gov. Robert Ehrlich's Office of Crime Control and Prevention is auditing a year's worth of statistics for the city and four other large Maryland jurisdictions to determine whether they have underreported crime more recently. O'Malley said the city's progress on violent crime- homicide, rape, robbery and aggravated assault- cannot be denied. He also said the police department's crime statistics are reliable despite recent gaffes in reporting."We police our own numbers pretty darn well," the mayor says.But O'Malley said he expects attacks. "If the state police wanted to do (an audit) they could. ... I hope your political antenna goes up if Ehrlich wants to do it this year."Crime experts, including an FBI agent working as consultant for the city, say a more accurate estimate would put the reduction in violent crime in Baltimore from 1999 to 2004 at less than half of O'Malley's claim, which would make it significant, but not nation-leading.Before the audit O'Malley ordered when he took office, the violent crime rate in Baltimore in 1999 was that decade's lowest. After the audit, 1999 became one of the city's most violent years in two decades, reversing a four-year trend of declining violence, records show.The extensive audit found that police had been mistakenly classifying violent crimes, especially aggravated assaults, as lesser and technically nonviolent offenses. Some criminologists question some of the reclassification techniques used in that audit six years ago, such as calling crime victims to get their recollection of events."He may be right in correcting what happened in 1999," says David B. Muhlhausen, a senior policy analyst specializing in criminal justice issues at the Heritage Foundation. "But I would be very suspicious that the year he comes into office he corrects the numbers and then says he drastically reduces crime."Several criminologists say O'Malley should not declare such a steep reduction in violent crime unless current crime reports undergo the same comprehensive scrutiny applied to the 1999 data."A better comparison would be the unadjusted numbers for 1999," says James Nolan, a West Virginia University criminologist and former FBI expert who was hired by the city to help devise the 1999 audit. By that measure, O'Malley's "nearly 40 percent" decline- actually 37.4 percent from 1999 to 2004- would drop to a 23.5 percent reduction in violent crime, the sixth-largest decrease among the nation's largest cities in that period."The only real accurate way to (determine the rate of reduction) is to do another audit," Nolan says.O'Malley says he encourages anyone to obtain police records and conduct a review. He says a comprehensive audit similar to the one in 1999 is unnecessary because the scrutiny applied six years ago helped establish a more accurate and thorough process for reporting crime.