The Cook County State’s Attorney’s Office (CCSAO) publishes five case-level data sets with information on approximately 400,000 defendants and 1,000,000 charges. Each data set represents one step in the lifecycle of a felony case, including intake, initiation, and disposition (of which sentencing and diversion are more detailed outcomes). The data includes only adult, criminal felony cases. Juvenile cases are not included.
Each table uses a different unit of measurement and the variables (columns) change across data sets. Please see the individual data set descriptions below for details. Case_ID and Case_Participant_ID are used as identifiers across all four data sets.
Download Cook County Felony Case Flowchart
Intake
The Intake data set illustrates the CCSAO’s first contact with a felony case, which often occurs through the Felony Review process. When an arrest is made, and if the law enforcement agency decides to charge the arrestee with a felony, the CCSAO’s Felony Review Unit (FRU) must be contacted for an Assistant State’s Attorney (ASA) to review the evidence and decide whether charges can be filed. Exceptions to the Felony Review process include narcotics cases and driving with a revoked/suspended license, which can be directly filed by law enforcement. In some instances, a case may also be directly indicted by a grand jury instead of going through the FRU process.
Data Structure
The Intake data set only includes information on cases received by the CCSAO. Each row represents a potential defendant in a case (thus, a given case can be referenced by multiple rows if it has more than one defendant).
Please use this glossary of terms to better understand the data.
What's in the Data
Felony Review Results
How to read the data
- Received_Date indicates when the CCSAO first received the case. Note that receiving a case is not equal to filing charges.
- Felony_Review_Result captures the most recent result of the FRU process. For cases directly filed by law enforcement or indicted by grand jury, Felony_Review_Result will remain as “Null” because the cases were not brought to FRU.
- Once law enforcement calls in a case, most common results from FRU are Approved, Rejected, and Continued Investigation (CI). Following an approval from FRU, a formal charge will be filed; at this point, the case will now appear, along with relevant information, in the Initiation data set. For cases rejected by FRU – unless police decided to file the case directly as a misdemeanor or re-present the case for a second review – no charges will be filed. A CI request indicates that more information is required to make a determination and that police have been instructed by the CCSAO to continue the investigation to prepare for an additional felony review and (eventually) subsequent approval or rejection.
- Felony_Review_Date captures the day of the felony review result. The data set does not reflect how a case was filed if it occurred outside of FRU (i.e. grand jury indictment or directly by law enforcement).
Initiation
An initiation is how an arrest becomes a “case” in the court system. In most instances, after an arrest, a defendant is taken to bond court where a judge determines whether the defendant should be released pre-trial and, if so, what conditions should be imposed on that release. In the following days or weeks, criminal court proceedings are formally initiated through either a grand jury indictment or through a finding of probable cause by a judge in a preliminary hearing. A case can also be initiated directly by grand jury without an arrest, this is called direct indictment.
Data Structure
The Initiation data set includes all charges that have been filed against a defendant. Again, multiple defendants may be associated with one case, and one defendant may be charged with multiple offenses. Therefore, each row represents one of the charges filed against one defendant in one case.
Please use this glossary of terms to better understand the data.
What’s in the data
Bond & Changes in Bond
Preliminary Hearing & Grand Jury Indictment
Finding No Probable Cause
Charges Initially filed
How to read the data
Charges Initially Filed
- Charge_Offense_Title indicates the offense the defendant is charged with at the start of a case. As a case evolves, the charges against a defendant may change (e.g., a charge can be dropped, or a specific offense may change).
- Charge_ID is a unique identifier for each charge against the defendant; it can be linked with the Dispositions dataset to find the ultimate charge(s) brought against a defendant.
Bond
Constitutionally, defendants are presumed innocent pre-trial. The purposes of bond are to protect public safety and ensure a defendant’s return to court. During bond court proceedings, ASAs present information and, when appropriate, make recommendations so that defendants who present a danger to public safety are detained, while those who are not a threat are subject to the least restrictive conditions of pre-trial release to ensure their return to court. ASAs may make recommendations, but the court ultimately sets the bond type and amount. Four types of bond orders, including no bond, can be set by a judge while an individual awaits trail.
- Bond data included in the Initiation dataset comprises initial and current status of bond type, bail amount, the date issued, and whether an electronic monitoring (EM) device was ordered.
- Bond_Type_Initial, Bond_Type_Current, Bond_Amount_Initial, Bond_Amount_Current all reflect the decision by bond court. The bond data does not include the CCSAO’s bond recommendation, the amount posted, or if the defendant bonded out.
- Bond status may change through the course of a case. The CCSAO tracks changes to bond status, specifically initial and most recently recorded bond status.
Example of a change in bond status:
Phase 1- the court set a $1,000 cash bond and no electronic monitor for defendant. Defendant doesn't like this result and decides to appeal.
Phase 2 - the court remade the decision and set a $500 cash bond but orders defendant to wear electronic monitor. The court's decision has changed, but the CCSAO is not made aware of whether defendant has paid and bonded out.
Types of bond available in Data Glossary
Dispositions
Data Structure
The Dispositions data set reflects the culmination of the fact-finding process that leads to the resolution of a case and its prosecutorial result. Each row in the Dispositions data set is a charge that has been disposed, meaning the case has been closed or completed. As discussed in the Initiation data set description, one defendant may face multiple charges in a case, and every charge ends up with a unique disposition (or result).
Please use this glossary of terms to better understand the data.
What’s in the Data
Disposition
Charges filed at disposition
How to Read the Data
- Disposition_Charged_Offense_Title indicates the ultimate charge brought against a defendant
- A charge against a defendant may change as a case evolves due to pleas or other circumstances. Therefore, Disposition_Charged_Offense_Title is the charge at the time the case is resolved and may be different from the original Charge_Offense_Title entered at the initiation stage.
- Charge_Disposition indicates the result of that charge (e.g., a defendant with Disposition_Charged_Offense_Title = “Criminal Sexual Assault” and Charge_Disposition = “Verdict Guilty” means that the defendant was found guilty for criminal sexual assault in a jury trial).
Sentencing
Following a guilty plea or guilty verdict in a trial, a judge holds a sentencing hearing which determines the conditions and length of punishment. The Sentencing data set includes information on sentence type (see Commitment_Type and Sentence_Type) and sentence length (see Commitment_Term and Commitment_Unit). The most common sentences for felony cases are prison, probation, jail, conditional discharge, supervision, or Cook County Boot Camp.
Data Structure
Each row in the Sentencing data set is a charge that has been sentenced. One defendant may be sentenced multiple times as they appeal the original sentencing decision or as other resentencing criteria are applied to a case. In this dataset, the latest sentence associated with a defendant is noted as Current_Sentence.
Please use this glossary of terms to better understand the data.
Key Information
Sentencing
How to read the data
A Current_Sentence noted as “0” indicates a non-current sentence. For example, a defendant sentenced initially with probation but who violated that probation will be resentenced making the new sentence the Current_Sentence and reflected with a “1”.
| Person | Sentence | Current_Sentence | Sentence_Time |
| A | Probation | 0 | 1-1-2019 |
| A | IDOC | 1 | 2-1-2019 |
Cases listed as dismissed/Nolle that contain sentence information are likely to have defendants who completed a diversion program that led to a case dismissal.
Diversion
Diversion can occur at many points throughout the criminal justice process. As the prosecuting body for Cook County, diversion for the CCSAO refers to connecting defendants to services and programs (e.g., assistance with substance abuse, employment, mental health treatment, etc.), rather than sentencing them to time in custody. ASAs screen cases and refer eligible defendants to diversion programs.
There are pre-plea and post-plea court-based diversion programs available in Cook County; five are pre-plea diversion programs overseen by the CCSAO, and three are post-plea programs overseen by the Office of the Chief Judge. Learn more about Cook County diversion programs.
Data Structure
The Diversion dataset contains information on defendants who receive a referral to a diversion program, including the type of program and date of referral; each row is a program to which a defendant has been referred.
Please use this glossary of terms to better understand the data.
What’s in the Data
Diversion programs
Diversion program results
How to Read the Data
- Diversion program outcomes are recorded in two tables:
- Diversion Table: Column Diversion_Result shows whether the defendant completed, failed, or is in progress of their program.
- Disposition Table: “Nolle Prosecution” in the Charge_Disposition column indicates cases that a prosecutor didn’t pursue charges. The Disposition_Reason column indicates cases that were dropped due to various reasons. Diversion programs are listed in Disposition_Reason when a prosecutor has filed “Nolle Prosecution” in the disposition, upon an individual's successful competition of a diversion program.
Even though the two columns are describing the same thing – the outcome of the diversion program – the numbers do not always add up due to multiple points of entry of the data. As a way to limit the modification of data, both columns are included in these datasets. When a referral date is not available, the earliest known date of participation in a diversion program is used.
Received_Date is often set to the day when the office first began data entry of this case. Most non-narcotics cases are first received by the CCSAO and entered in real-time during the Felony Review process. However, since narcotics cases are initiated directly by law enforcement and do not undergo the Felony Review process, case information for narcotics charges are not entered into the database until after bond court and diversion program referral.
For narcotics cases where a defendant is referred to a diversion program however, the Received_Date is recorded as occurring after a program Referral_Date (i.e., the date CCSAO refers a defendant to a diversion program). This occurs in 4,000 of 20,000 diversion cases in our data. Among these 4,000, 90% only have a time difference of only a few weeks.
If you are interested in working with the SAO on quantitative research that depends on more, or different, data than the case-level datasets provide, please Submit a Data Request using this form so we can work to support you.
Questions about the case-level datasets, public analysis, data resources, and anything else can be directed to SAOData@cookcountyil.gov.