Illinois Prison Dashboard

Glossary

Charge Levels

A criminal case may involve multiple charges. Across this dashboard, cases are grouped into the following mutually exclusive categories based on the most serious holding charge, as identified by the Illinois Department of Corrections.

Felony: A crime punishable by a term of imprisonment of not less than one year. In Illinois, felonies are divided into six classes: Murder, Class X, Class 1, Class 2, Class 3 and Class 4 (least serious). Sentences following conviction for a felony may include fines, probation, jail, and prison. Prison is mandatory for Murder and Class X felonies.

Misdemeanor: Misdemeanors are less serious criminal violations of Illinois state laws, punishable by a sentence of up to 364 days in county jail. A person convicted of a misdemeanor cannot be sentenced to state prison, unless the misdemeanor sentence is served simultaneously (concurrently) with a felony sentence. In Illinois, misdemeanor offenses are divided into three classes, with Class C being the lowest level of misdemeanor and Class A the most serious. Sentences following conviction for a misdemeanor may include fines, probation, and jail.

Charge Types

Person: Includes homicide, battery, aggravated assault, aggravated vehicular hijacking, domestic battery, reckless endangerment, child abuse, kidnapping, human trafficking, false imprisonment, stalking, menacing, extortion, neglect, violation of order of protection/restraining order, and robbery; as well as any sex offense such as sexual assault (including sexual assault on a child and sexual assault on a child by one in a position of trust), sexual contact, sexual exploitation, incest, enticement, internet luring, sexual human trafficking, prostitution charges, indecent exposure and public indecency, and some invasion of privacy charges.

Weapon: Includes possession of a weapon, including a handgun, carrying a concealed weapon, prohibited use of a weapon, illegal discharge, straw purchase, and other weapons charges.

Property: Includes arson, burglary, forgery, fraud, cybercrime, defacing property, identity theft, motor vehicle theft, theft, retail theft, and trespassing.

Drug: Includes possession of a controlled substance charges, possession with intent to distribute, distribution (including marijuana), manufacture of controlled substance, possession/sale of drug paraphernalia, and other drug charges.

DUI/Vehicle Offense: Includes driving under the influence of alcohol or drugs charges, as well as other vehicle related offenses including reckeless driving, driver’s license violations, driving on a suspended/revoked license, driving without insurance, leaving the scene of an accident, and other vehicle/traffic charges.

Public Order/Other Offense: Includes obscenity, contributing to the delinquency of a minor, bribery, disorderly conduct and official misconduct, false report/emergency, escape, introduction/possession of contraband in detention, obstruction of an officer/official, perjury, resisting arrest, violation of bail bond or custody, alcohol offenses, cruelty to animals, gaming/gambling, fleeing/eluding police, and offender registration violations.

Demographics

Age: Defendant age is calculated at the time the time of sentencing for prison admissions and at the time the population is counted for prison populations and exits.

Sex: Sex is defined as the Sex category as recorded and reported by IDOC. This does not reflect the individual’s gender identity, but what was recorded in the tracking system of record at the individual’s admission to IDOC custody.

Race: Race is defined as the racial category as recorded and reported by IDOC. IDOC reports the following categories: White, Black, Hispanic, Asian, American Indian, Biracial, and Unknown. For the purposed of these dashboards, American Indian, Biracial, and Unknown have been combined into “Another Race/Ethnicity".

Data Terms

Average: The average of a set of numbers is the sum of the numbers divided by the total number of values in the set. For example, to find the average of 24, 55, 17, 87 and 100, first find the sum of the numbers: 24 + 55 + 17 + 87 + 100 = 283 and divide by 5 to get 56.6.

Median: The median is the value separating the higher half of a data sample from the lower half. It may be thought of as the "middle" value of a data set. For example, in the data set 9, the median is 6, the fourth number in the sample.

Outlier: An outlier is a data point that differs from other observations, is much bigger or much smaller.

Methods

This dashboard aggregates data from the Illinois Department of Corrections.

We present data in four sections, summarizing information about prison admissions, prison populations, prison exits, and MSR populations. In each section we present general trends and an overview of cases and characteristics. The same defendant may appear in the dashboard in multiple ways. For example, a person admitted in FY25 would be presented in the admissions dashboard, the prison population dashboard and, (if released within 12 months) in the exits and MSR dashboards.

Prison

The dashboard relies on prison data obtained from the Illinois Department of Corrections' (IDOC) online public data portal to determine admissions to prison, releases from prison, and prison population. These data are at the individual level, although the same person could be admitted to or released from prison multiple times. The offense level and offense type are for the crime that will keep/kept the individual in prison the longest when the individual was sentenced to prison. For individuals admitted to prison for technical violations of their Mandatory Supervised Release (MSR), the offense level and offense type are for the offense that originally resulted in their sentence to prison. For releases from prison, the years in custody includes time served in prison plus time served in pretrial detention or on pretrial electronic monitoring credited to the sentence by the sentencing judge. The releases from prison are those individuals sentenced to prison from Cook County who were released, not necessarily being released back to Cook County (although most sentenced from Cook County do return to Cook County). The admissions to and releases from prison count the number of individuals admitted and released during the time periods, while the prison population is counting individuals in prison on the last day of each quarter/year.

MSR (Parole)

The dashboard relies on Mandatory Supervised Release (MSR) data obtained from the Illinois Department of Corrections' (IDOC) online public data portal to determine the parole population. The offense level and offense type are for the crime that kept the individual in prison the longest when the individual was sentenced to prison. The MSR population is the count of people on MSR who are living in Cook County at the last day of the quarter/year, regardless of the Illinois county in which they were originally sentenced to prison. For those on MSR in Cook County, there is a tab indicating in which county the original prison sentence was imposed.