_ In Chicago and other big cities, police can enter an address of a crime in a computer and automatically get detailed maps and information from police databases, right down to computerized mug shots of criminals known to live nearby.

_ In some parts of the country, cops with GIS-equipped computers in their cars can instantly access information from city tax records and other databases to get everything from the size, occupancy and layout of houses, right down to the locations of doors and potential hiding places.

"You might not need that sort of information every day, but when it's three in the morning and you're doing a raid for drugs, you're going to want to know," said Thomas Geagan, systems administrator for the police department of Newton, Mass., near Boston.

GIS technology is nothing new _ its roots go all the way back to the 1960s.

Today, about 97 percent of all municipalities with more than 100,000 people use GIS in some fashion, according to a survey last year by Public Technology Inc., an organization of government officials.

Until fairly recently, though, the world of GIS has generally been limited to city planners, engineers and tax assessors, who use it to map streets and sewer lines or figure out the value of property.

Some police and public safety departments started using GIS in the late 1990s.

But between the increased push for homeland security and the declining costs of technology, GIS has taken on a new emphasis for public safety and law enforcement in many communities.

"We saw a big explosion in this three or four years ago, but we're seeing a second big explosion today," said Lew Nelson, who heads the public safety and law enforcement division of Environmental Systems Research Institute Inc. or ESRI, a pioneering purveyor of GIS software.

"Because of homeland security issues, people are staring to realize that geography is important," Nelson said.

Cops, of course, have known the importance of maps, data and statistics ever since the earliest days of detective work.

What's different about GIS technology is that it allows them to tap into databases more quickly and thoroughly than ever before, and makes all of it easier to visualize and use by correlating it to maps.

"You can look at a piece of paper with addresses (of crime incidents) but you could never know they're right next to each other," said Sgt. David Ferguson, a crime analyst at the Atlanta Police Department.

Of course, computers and maps can only make up for so much gumshoe detective work.

And many times, police and firefighters are too busy responding to calls to spend time sifting through reams of data looking for patterns, even if computers and GIS technology lets them do it faster.

Meanwhile, as municipalities across the country struggle with budget woes, buying more computers and paying people to figure out how to use them often takes a back seat to more pressing needs.

"There are a lot of law enforcement jurisdictions where simply getting tires and radios for police cars can expire the entire budget," said Paul Taylor, chief strategy officer for the Center for Digital Government, a research and advisory group. "GIS looks way out of reach for many decision-makers."

That said, local and federal government spending on GIS software is expected to grow by about 11 percent to $400 million this year, according to technology market researcher Daratech Inc. Law enforcement and public safety related purchases are helping lead the growth, said Daratech senior analyst Monica Schnitger.

Johnson, of the Austin police department, said GIS technology is becoming indispensable in his work.

"It's becoming just an important of a tool in crime analysis as a word processor or spreadsheets," he said.

Bob Keefe's e-mail address is bkeefe(at)coxnews.com

LOAD-DATE: August 20, 2004