Want a reduction in crime statistics? Just stop counting all crimes.
Both the cities of Dallas and New York have employed this simple technique.

The City of Dallas finished 2009 with a 6.4 percent drop in reported crime from the year before, according to the figures released by the Dallas police. However, the 2009 total count of 81,585 crimes does not include some crimes that should have been counted, according to federal guidelines.
Police are supposed to collect crime statistics in accordance with federal guidelines in the Uniform Crime Reporting Program (UCR), which is run by the FBI Law Enforcement Agencies. The Dallas Police Department’s reporting system deviates from federal guidelines in several areas that would undercount crimes and reduce the overall crime rate.
The Police Department understates and misclassifies many aggravated assaults so they are not included in the city’s violent crime tally. And, the department continues a long-standing practice of classifying break-ins as vandalism, not burglary, if someone kicks in the door of a residence but is scared away by a person or an alarm.
As a result of reporting changes made in 2008, Dallas Police are discarding legitimate car burglary reports as “untrustworthy” even though an epidemic of broken car windows has led to the proliferation of “Lock and Hide” signs throughout the city.
All of these manipulations in Dallas are deviations from federal guidelines.
As New York City has consistently reported annual reductions in crime, skepticism is pervasive among members of police unions, elected officials, and residents in some neighborhoods, that the Police Department’s books are being “cooked.”
In an anonymous survey, more than a hundred retired New York Police Department captains and higher-ranking officers said that the intense pressure to produce annual crime reductions led some supervisors and precinct commanders to manipulate crime statistics.
Precinct commanders or other officials sometimes went to crime scenes to persuade victims not to file complaints or to urge them to change their accounts in ways that could result in the downgrading of offenses to lesser crimes
Senior officers retired from the New York City force cited a periodic practice among some precinct commanders and supervisors: Checking eBay, other Web sites, second-hand catalogs or other low-value price listings to find prices for items that had been reported stolen that were lower than the value provided by the crime victim. The police would then use the lower values to reduce the reported grand larcenies to misdemeanors and therefore not reported in the publicly released statistics.
Recommendation: As more and more citizens are losing faith in their governments, transparency and honesty in reporting is essential. The FBI UCR program auditors should make a thorough review of the released crime statistic reports of Dallas and New York City.