McHenry County Sheriff's Office, Huntley police make crime maps available

Using data to determine crime trends and target hot spots in the community is not a new policing phenomenon.

But putting that information online is.

A growing number of area police departments – such as the McHenry County Sheriff's Office and more recently in Huntley – have made their crime maps available to the public as a way to help prevent crime through a well-informed public.

The Sheriff's Office's intelligence-led policing efforts have allowed authorities to target high-crime areas in the county and turn it into a map. The map then strips what Sgt. Mike Muraski called "law enforcement sensitive" data, and makes it available for public consumption.

The idea is two-fold. One: target high-crime areas by padding patrols and police presence, and two: have the public's involvement to help reduce crime.

Huntley modeled its crime map after the maps used at the Sheriff's Office.

"It allows us as a department to understand where crimes are occurring and identify hot spots," Huntley Police Sgt. Amy Williams said.

Data for these crime maps are pulled from police records. Names and exact addresses are removed for the public version. While Huntley leaves off domestic violence incidents, medical calls and traffic stops, the sheriff's office lays it all out there. There usually is a 24-hour lag time before the maps are updated.

Huntley began its public crime mapping tool in a response to a community survey that demanded one. It launched last fall. Because it's so new, significant crime drops are yet to be seen.

Muraski explained that it's difficult to determine the effect of these resources, because there's no way to analyze crimes that did not occur.

"It's a tool, it's not a crystal ball," Muraski said of the public map that launched in 2012. "The computer crunches the numbers and says there's a high probability a crime is going to occur in this area, based on past data."

Still, armed with data, Muraski and the four-deputy unit are able to forecast where a crime is likely to occur, and can deploy deputies in the target area or increase police presence.

The sheriff's office crime information is only for unincorporated areas of McHenry County, although assists to other agencies are coded. Searches can be done for the entire county by township or nearby city. Both Huntley and the sheriff's office maps are broken down into type of crime, and color coded icons are placed on the location where the calls came from.

Critics of crime mapping said there were obvious problems for small agencies in truly being able to analyze the data and determine trends. Some have called for a map inclusive of all county police agencies that would be better for catching larger, wide-scale crime rings.

Still, Williams noted the benefits of arming the public with information on where crimes are occurring in their neighborhoods.

"The most important thing is having an informed public," she said. "If they see on the map that there's been car burglaries in their neighborhood, hopefully that reminds them to lock their own doors. If they they see someone suspicious … maybe they'll make a [police] report."