Modern Mapmaker

Grass-roots combination of GIS and Google improves access to Chicago crime information.

by / August 31, 2005
Sometimes simple things make all the difference. was launched in May by 24-year-old Chicago resident Adrian Holovaty, because, as he put it, it was an interesting technical challenge and a chance to help the community.

"My background is pretty evenly split between journalism, databases and computer programming, and this was an opportunity to combine all three," Holovaty said. "My goal for the project was to create a useful resource for Chicagoans."

Despite lacking a GIS background, he built from scratch to take publicly available data from the Chicago Police Department's official Citizen Information Collection for Automated Mapping (ICAM) Web site and integrate that data with Google maps.

It shows detailed hour-by-hour lists of all crime reports in a public service twist on what some have started to describe as a "Google hack" -- creatively harnessing Google's powerful tools to enrich specialized Web sites.

Public Eyes
Because Google charts each point on its maps by latitude and longitude, Web developers have started to match up these points with other databases, producing GIS displays of information for such things as reported crimes in Chicago, real-estate listings in New York and sex offenders in Florida.

"I was looking for a side project to work on when I stumbled upon the Citizen ICAM site," Holovaty said. "That site is very useful, but I thought I could create a site that supplemented it by offering additional ways of sorting and searching the data." lets users search for crimes by type, such as arson, homicide, assault or gambling. It allows people to browse streets and map nearby crimes. They can also search by ZIP code, police beat or specific kinds of locations, such as ATMs, Chicago Transit Authority train stations, gas stations or bowling alleys.

Citizen ICAM only gives access to 90 days worth of crime data, and there is a one-week delay before crime reports are available. Because gets all its data from Citizen ICAM, this site has the same limitations. Despite the lag, Holovaty said, the site presents information in a new way that's useful to concerned citizens.

Even the Chicago Police are impressed with the result. "We think it's great," said Jonathan Lewin, commander of the Information Services Division of the Chicago Police Department. "It's very innovative, taking data that we're already publishing on our crime site, which has been up since late 2000. By repackaging that information, presenting it in a highly interactive way with hyperlinks all over the place, it is easy to explore and to drill up and down in the data. It does some creative things with mapping."

Lewin said he and his whole staff of managers have already met with Holovaty.

"If anything, I want to strengthen our partnership with him because I think this improves our ability to better engage the community as part of our policing efforts," Lewin added. "That's the whole basis of everything we are trying to do, and we want to expand the amount of information we make accessible to citizens."

Holovaty's site is built using open source software -- Apache Web server, the PostgreSQL database server and the Python programming language.

"I chose these technologies because they're the best tools for the job," he said.

In total, Holovaty estimates that he has spent about 50 hours on, and Web designer Wilson Miner estimates an additional 30 hours on the design and presentation.

"Since its launch, I haven't spent much time on it, other than adding a few features such as color-coded map markers and ZIP code browsing," Holovaty said.

The site updates itself automatically each night.

"Unfortunately the ICAM site doesn't provide an RSS feed or any other sort of data-export capability, so my program does screen scraping, which is essentially retrieving a Web page and programmatically 'reading' the page to grab the data," Holovaty explained.

The Chicago Police Department is considering changing this, according to Lewin.

"Naturally we've talked about giving him a more direct feed because right now he is scraping the Citizen ICAM Web site every day," Lewin said. "We are more than willing to work with him or anybody else that is doing anything innovative."

But for the moment, Holovaty is largely content to let the site run itself.

"The only standard maintenance I do, other than adding features, is checking the site every once in a while to make sure Google maps hasn't changed its code," he said. "That's only happened once. Otherwise, if something goes wrong, the system automatically sends me an e-mail."

So far, feedback from citizens has been overwhelmingly positive, Holovaty said, recalling one example of a citizen who e-mailed him to say he's been using data from to convince his alderman that a particular intersection needs brighter lights at night.

The site has also started to generate considerable attention beyond Chicago. Several police and government departments have approached Holovaty asking for help with their Web sites -- particularly about adding crime-browsing features similar to those of

Holovaty said he's also been contacted by a couple dozen nongovernment organizations asking for help with adding Google maps to their sites. What started out as a technical challenge and community service just might turn into a career.

Because of all the interest from organizations wanting similar features on their Web sites, Holovaty and Miner are developing standard pricing to create similar Web sites for paying clients.

"From my limited experience looking at other such packages, ours is much less expensive and better software than the currently existing proprietary tools on the market," Holovaty said. "Also, it's based on open source technologies, which means there's no vendor lock-in."

Given the effectiveness of so far, it could be what groups wanting a similar kind of Web site might turn to in the future.
Blake Harris Contributing Writer