Mapping Crime; Police around world are using technology to anticipate where the bad guys will strike next.

Byline: Mac Margolis (With Steven Ambrus in Bogota and Sumeet Chatterjee in Mumbai)

A decade ago, BogotA had a bad name. Violent crime was out of control. Rather than simply buying more guns or patrol cars, BogotA's cops went for something bigger: science. The city began superimposing millions of police bulletins onto digitized city maps to pinpoint which bandits were at work and where, down to the doorstep. By displaying crime data on easy-to-read city maps, police were able to target urban hot spots and optimize street patrols. Murders have since fallen by a third in the past five years and the police's approval rating has soared. "Crime mapping has made us faster and more efficient," says Gen. Luiz Alberto Gomez, head of BogotA Metropolitan Police. "We are serving the neighborhoods better."

So are police in several countries, as the virtues of high-tech crimefighting become clear. Spiking crime rates everywhere from Colombia to Brazil, India to South Africa, have encouraged more and more cops to draw on technology to anticipate where criminals are going to strike next, so their thinly stretched forces can be at the right place at the right time. "Without computerized crime analysis," says Alexandre Peres, a government security strategist in Pernambuco, northeast Brazil, "policing is guesswork."

The trend goes back to the early 1990s, when New York City police started using CompStat, a computer-driven mapping tool. In the next decade or so, violent crimes tumbled by 70 percent; the city now ranks 222nd in the country in crime. Major cities across the United States and Europe followed New York's lead, and now the rest of the world is catching on. Colombia began arming police with printouts of satellite maps annotated with crime data to show neighborhood trouble spots. In half a decade homicide rates plummeted in BogotA (by 30 percent), Medellin (35 percent) and Cali (25 percent). Sao Paulo tripled its budget in security technology and has seen its murder rate fall by half since 1999, when the Infocrim crime-monitoring system was installed. India and South Africa have started similar programs. Police and crime analysts crisscross the globe to attend crime-mapping conferences.

Cheaper technology is a big reason for the boom in crime mapping. Tools range from $50,000 I2 "kernel density" software, which can sniff out elaborate financial transactions, to $1,600 mapping programs, to Google Earth. Rather than sticking colored tacks on paper maps, crime strategists stick virtual pushpins into computerized street maps, flagging each zone with essential data gleaned from criminal archives, demographic data and even social indicators like poverty and urban blight. If police blotters show a recent surge in muggings in an ...