All too many crimes go unreported to authorities and thus never enter the criminal justice system; these crimes are often referred to as the "dark figure" of crime because they go uncounted in police statistics. Calculating the rate at which crimes go unreported in a specific jurisdiction is very hard. This is why the United State's Justice Department created the National Crime Victimization Survey (NCVS). This research helps the justice department measure how many people are victims of certain kinds of crimes, or the victimization rates. While this research is done nationally, we can use it to estimate how many more victimizations are occurring in Chicago than the Chicago Police Department is able to report.

These numbers are presented to educate the public about the fact that too many victimizations never result in a call for help. That the facts and figures released each year by justice agencies only pertain to the crimes that entered the justice system, and many for which there is no direct victim. We understand that the numbers are not exact and should not be interpreted as such, but they should be relatively close to the number of unreported crimes in Chicago.

Using data from the National Crime Victimization Survey from 2012, we are able to calculate a very rough figure for the number of victimizations that occur in Chicago. The incident data from the Chicago Police Department is also from 2012 and was taken from the Chicago Police Department's "Domestic Violence Statistical Summary, Year to Date-December 2012", and from a data request submitted to their Research & Development Division.

Rates of Report for Victimization

Percent Reported

Police Reports

Actually Occurred

Sexual Assault




Domestic Violence




Agg. Assaults


Simple Assault




Vehicle Theft




We are awaiting more data for this chart from the Chicago Police Department. Updates will follow soon.

This project is part of the Smart Chicago Collaborative's Civic Works Project, a program funded by the Knight Foundation and the Chicago Community Trust to spur support civic innovation in Chicago.

Our partners for this project are Chicago Justice Project, a nonprofit research organization, and FreeGeek Chicago's Supreme Chi-Town Coding Crew (SC3). You can find the code backing this website on Github. We used the Chicago Tribune's Tarbell content management system to build our site. Content and code is under a Creative Commons Attribution 3.0 Licence.