July 7, 2010

I. Methodology

This report relies on data collected by Human Rights Watch over the course of an ongoing, 10-month investigation into rape kits in Illinois. During the course of our research, Human Rights Watch conducted 304 telephone or in-person interviews with police officers, chiefs of police and police executives, crime lab personnel, crime lab directors and officials, sexual assault forensic nurses, rape treatment providers, elected city officials, victims of rape, family members of rape victims, rape victim advocates, state and city sexual assault organization directors and senior staff, national sexual assault and victim’s rights organizations’ directors and senior staff, senior staff at the US Department of Justice Office of Justice Programs, civil attorneys, public defenders, county attorneys, state legislators, officials at the Illinois Office of the Attorney General, local newspaper reporters who have covered the issue of rape kit backlogs extensively, and statisticians from state and city criminal justice statistics offices.

We conducted on-site visits to the Illinois State Police crime labs and evidence storage facilities in Springfield and Chicago.

We submitted more than 260 requests under the Illinois Public Records Act to every county and the most populous cities in the state, as well as to the Illinois State Police crime laboratory system. We requested rape reporting, arrest, prosecution, conviction, and dismissal rates, and documents pertaining to the collection, processing, and backlog of rape kits. The records requests were mailed out of Human Rights Watch’s Washington, DC, office on or around June 9, 2009, and analysis began in late April. Any information received after we began data analysis was not included in the report.

Data Analysis Methodology

Data arrived from city and county law enforcement agencies in a variety of formats. While some departments provided data in aggregate form, others submitted electronic and paper files of individual cases. When individual case files were submitted, Human Rights Watch staff compiled and aggregated statistics. Data was then entered into a database and subsequently cleaned for errors. All data analysis was completed using statistical software (SPSS v.17).

In addition to the data obtained through our public records requests, Human Rights Watch obtained data on reported rape and rape arrests from the Illinois Uniform Crime Reports.[19] Population and demographic data for selected cities and counties was obtained from the American Community Survey 3-year estimates (2006-2008).[20] Data analysis mainly consisted of descriptive statistics including frequencies, rates, and cross-tabulations.

While Human Rights Watch’s public records requests asked for data corresponding with the years 1995 through 2009, agencies provided data for an assortment of years. Some agencies provided reported rape and arrest data for one set of years, and rape kit testing data for a different set of years. When this occurred, analysis of the rape kit data only included reported rapes and arrests from the corresponding years.

There were three cities (Du Quoin, Charleston, and Centralia) where the years for rape kit data and the corresponding years for reported rapes and arrests could not be isolated because reported rape and rape arrest data was aggregated, making it impossible to extract data from specific years. In these cases, estimates for year-specific reported rapes and arrests were generated assuming a linear trend in rapes and arrests.

Human Rights Watch requested information from 264 law enforcement agencies and received no response from 80 departments (30.3 percent). An additional 36 (13.6 percent) agencies that did respond to the initial request refused or failed to provide us with the requested data. Seventy (27.2 percent) agencies provided Human Rights Watch with all of the data requested while 78 (29.5 percent) provided at least partial answers to our requests.[21]Of those agencies that provided Human Rights Watch with full or partial data, 104 were city police departments and 44 were county-level agencies.

Data requests were sent to 162 cities. Human Rights Watch received no data from 58 city police departments, partial data from 55 departments, and complete data from 49 cities. Of the 20 largest cities in Illinois, Human Rights Watch received partial or complete data from 15 police departments. Human Rights Watch also requested data from 102 county sheriff’s departments. Twenty-one counties provided complete data, 23 provided partial data, and 58 counties did not provide data.

The majority of the data sent by agencies failed to fully comply with the public records request. Only 33 percent of the agencies responded with data that was complete or did not include errors. The most common errors concerned the lack of information (either not answering a question, or responding that they did not know the answer to a question) on the status of rape kits including whether or not they were tested and where they were being stored.

Of the 148 agencies that responded with data to our public records request, 85 percent provided information on rape kits. However, data provided on rape kits, including the end-results of rape kits, was often incomplete, uncertain, or unknown. While most departments that responded could provide a total number of rape kits collected, many could not determine the destinations or final results of the kit. In many cases, departments required Human Rights Watch to comb through boxes of evidence they provided in response to our request in order to investigate final destinations of rape kits. Given these failings, the total statistics aggregated here cannot be assumed to tell the entire story of DNA rape kit processing in Illinois. Nevertheless, the data in this report are the best possible estimates of the administering, collection, processing, and storage of rape kits in Illinois given the data presented by law enforcement agencies.


[19] Illinois State Police, “2008/2007 Crime Index Offense and Arrest Database,” http://www.isp.state.il.us/crime/cii2008.cfm (accessed May 13, 2010).

[20] US Census Bureau, “2006-2008 American Community Survey 3-Year Estimates,” http://factfinder.census.gov/servlet/DatasetMainPageServlet?_program=ACS&_submenuId=datasets_2&_lang=en&_ts= (accessed June 16, 2010).

[21] Numbers do not add up to 100 percent due to rounding.