Glossary & Methods

Legal Terms

Appeal: A defendant can appeal their pretrial detention, conviction, or sentence to a higher court. They must file the appeal within a certain timeframe, as required by state law.

Appearance: A scheduled court hearing to which the defendant appeared or attended.

Arrest: Law enforcement takes an individual into legal custody based on suspicion of committing a crime. Officers use the standard of “probable cause,” informed by witness statements or other evidence, to determine whether an arrest is warranted.

Arrest warrant: A court issued legal document authorizing law enforcement to arrest an individual.

Bail or bond: The amount of money set by the court for the release of a person accused of a crime. It is intended to ensure the person’s appearance for trial and may include non-monetary conditions of release. This term only applies to cases presented prior to the Pretrial Fairness Act (PFA) that eliminated cash bail.

Beyond a reasonable doubt: The legal burden of proof required to convict a defendant in a criminal trial. The prosecution carries this burden of proof.

Bond hearing: If in custody a bond hearing is held to provide argument, evidence, or testimony for the Court to use in determining an appropriate amount of bail to be set for a defendant. This term only applies to cases presented prior to the Pretrial Fairness Act (PFA), which eliminated cash bail.

Case: A case is a collection of all charges against a defendant arising out of a single incident.

Case filing: Case filing refers to the formal submission of criminal charges against an individual to the court.

Charge: The formal accusation by a governmental authority that an individual has committed a crime.

Citation: A criminal citation is a formal notice issued by law enforcement, sometimes in lieu of arrest, informing an individual that they are accused of violating a criminal law or ordinance, and that they are required to appear in court to answer the charges. Someone can also receive a citation after they have been arrested but when they are released from police custody without being sent to court.

Continuance: A postponement in legal proceedings granted by the Court.

Conviction: The outcome of a criminal case when a defendant is determined to be guilty of a crime.

Crime: An act prohibited by statute punishable as a public offense.

Defendant: The person against whom a criminal case is pending.

Direct filing: Law enforcement may directly file some felony charges and all misdemeanor charges with the court without review by the State’s Attorney’s Office.

Felony review: Law enforcement presents felony arrests to the State’s Attorney’s Office for review, where a prosecutor determines whether to approve or reject charges or recommend continued investigation. If a prosecutor approves charges, then a criminal case is formally charged.

First appearance: The first point after initiation of a case in which the judiciary is involved, advising defendants of their constitutional rights, determining eligibility for public defense services, setting or modifying conditions of pretrial release or pretrial detention, and setting of future proceedings.

Grand jury indictment: The prosecutor may present charges to a grand jury - a jury of citizens who determine if there is probable cause to charge a defendant. Approval of charges by a grand jury is called an “indictment” or “true bill.”

Hearing: Any formal proceeding in court in which evidence is presented and/or arguments are made in favor of a certain outcome on a case.

In custody: When an individual is being detained by law enforcement, the court, or another legal entity and is not free to leave.

Plea agreement: An agreement between the prosecution and the defendant defining the specific conditions and crimes to which a defendant chooses to plead guilty and the court accepts the conditions of that agreement.

Pretrial detention: Defendants who are detained pretrial are incarcerated in jail prior to resolution of the case. This applies to cases presented both before and after the implementation of the Pretrial Fairness Act (PFA).

Pretrial Fairness Act: The Pretrial Fairness Act (PFA), part of Illinois' SAFE-T Act, eliminates cash bail and reforms pretrial release practices.

Pretrial release: Defendants who are released pretrial prior to resolution of the case.

Probable cause: Evidentiary reason for arrest or to obtain a warrant. A reasonable basis for believing that a crime has been committed.

Victim: A victim is a person who has suffered direct or threatened physical psychological, or financial harm as a result of the commission or attempted commission of a crime.

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 charge filed in the case.

Felony: A crime punishable by a term of imprisonment of not less than one year. In Illinois, felonies are divided into five classes, with Class 4 Felonies being the lowest level of felony and Class X the most serious, and murder (as a separate class). Sentences following conviction for a felony may include fines, probation, jail, and prison.

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.

Petty Offense/Infraction: Petty offenses are the least serious criminal violations of Illinois state laws. Infractions relate only to very specific (not all) charges involving use and possession of marijuana and certain traffic violations. Infractions may be paid without making a court appearance. All offenses not categorized as a misdemeanor or felony are captured here.

Charge Types

A criminal case may involve multiple charges. Across this dashboard, cases are grouped into the following mutually exclusive categories based on the most serious charge filed in the case.

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.

Detainable Case Types

Under the Pretrial Fairness Act (PFA), pretrial release (with or without conditions) is required for most defendants. There are only two groups of individuals who are initially detainable under the PFA: 1) those eligible for detention based on a “public safety” consideration, and 2) those eligible for detention based on a “willful flight” consideration. The public safety consideration allows for the pretrial detention of individuals charged with specific offenses if the State's Attorney files a petition to detain and proves that the defendant poses a real, and present threat to any person or the community. The willful flight consideration allows for the pretrial detention of individuals charged with any felony eligible for detention based on safety as well as any Class 3 Felony or more serious felony offense if the State's Attorney files a petition to detain and proves that the defendant poses a risk of willfully not returning to court.

The PFA does allow for detention in some cases based on prior convictions. However, this dashboard’s data does not currently include detailed criminal history information and cannot accurately identify cases where this provision is applicable.

For the purposes of this dashboard, cases are grouped into four mutually exclusive categories based on the types of offenses charged in the case. While the PFA created these new categories of detainable and non-detainable cases, we apply these categorizations to all cases before the PFA as well to show trends in cases and case outcomes over time across these groups.

Detainable public safety case: Cases in which a defendant is charged with an offense that is detainable under the public safety considerations under PFA provisions, including: any forcible felony; any felony for which a mandatory term of incarceration is required after conviction; most weapon offenses (primarily illegal firearm possession); most sex offenses; or, any felony listed in 725 ILCS 5/110-6.1.

Detainable domestic violence or violation of an order of protection case: Cases in which a defendant is charged with a misdemeanor or felony domestic battery offense or violating an order of protection. Domestic battery and order of protection violations are listed in 725 ILCS 5/110-6.1 as detainable offenses under the public safety consideration noted above. These offenses are categorized separately in this dashboard.

Detainable willful flight case: Cases in which the defendant is charged with any offense that would be detainable under the willful flight consideration of the PFA (all Class 3 Felony or more serious felony offenses). Cases are included in this category only if they do not include offenses detainable under the public safety consideration of the PFA or detainable domestic violence or violation of an order of protection offenses.

Non-detainable case: Cases in which the defendant is charged with an offense for which the defendant could not be detained under the PFA. This includes most Class 4 Felony offenses and most misdemeanor offenses.

Felony Review Outcomes

When an individual is arrested for a felony crime, the case is referred to the Cook County State's Attorney's Office for review. Misdemeanor crimes - as well as felony drug offenses and some weapon offenses - are direct filed in court by law enforcement and do not go through the felony review process.

Felony cases reviewed by the State's Attorney are categorized into the following mutually exclusive categories.

Rejected for Prosecution: A case is rejected for prosecution when all charges in a case referred to the prosecutor by law enforcement are fully rejected. All charges in a case may be rejected for any number of reasons, including lack of sufficient evidence.

Returned for Advice or Continued Investigation: A case is returned for advice or continued investigation when all charges in a case referred to the prosecutor are returned to law enforcement for further action.

Approved for Prosecution: A case is approved for prosecution when any charge(s) in a case referred to the prosecutor by law enforcement is approved and formally charged as a felony by the prosecutor. A case is considered approved even if some charges referred by law enforcement are rejected or returned for advice/continued investigation; if any one charge is approved the case is categorized as approved.

Dispositions

A criminal case may involve multiple charges, and each charge will have its own disposition. For example, at trial some charges in a case may result in a finding of guilt while other charges may result in a finding of not guilty; similarly, some charges in a case may be dismissed while other charges may result in a guilty plea.

Across this dashboard, each case is categorized by a single disposition based on the combination of dispositions across charges, as noted below. For example, if any charge in a case results in a guilty plea, finding of guilty, or verdict of guilty, the case is categorized as guilty. If all charges in a case are dismissed, the case is categorized as dismissed.

In some instances, cases may receive diversion - an alternative case resolution that can take many forms, but usually occurs pre-plea and involves a suspension of formal criminal proceedings against a defendant while they engage in certain conditions (such as treatment that addresses the underlying causes of criminal behavior). Generally, if a defendant successfully completes diversion, the charges in their case are dismissed. However, the data currently used for this dashboard do not include detailed information on diversion and, as such, are unable to accurately identify all cases in which a defendant is diverted; as a result, cases in which a defendant successfully completes diversion are likely categorized as dismissed and cases in which a defendant did not successfully complete diversion are likely categorized as another disposition in the dashboard.

Nolle Pros: A case is categorized as nolle pros when, after a case is charged, a prosecutor voluntarily dismisses all charges against the defendant. This means the prosecutor has decided not to proceed with the case for any number of reasons, but it is not the same as a disposition of not guilty (acquittal).

Dismissed or Stricken Off Leave to Reinstate (SOL): A case is categorized as dismissed when all charges in the case are terminated after the case is filed, either by the court or by the prosecutor. There can be several reasons for why a case is dismissed, including a lack of evidence or unavailability of a witness, or as part of a plea agreement.

Not Guilty (Acquittal): A case is categorized as not guilty when a judge or jury at trial determines that the defendant is not guilty of the offense(s) for which the individual has been charged.

Guilty: A case is categorized as guilty if any charge results in a guilty plea, a finding of guilty, or a verdict of guilty. A guilty plea results when the defendant admits a factual basis for the plea and acknowledges guilt for any charge filed or for any amended charge; a guilty plea must be agreed to and accepted by the Court. A finding of guilty results when a defendant is found guilty of any charge at a bench trial. A verdict of guilty results when defendant is found guilty of any charge at a jury trial.

Sentences

Across this dashboard each case is categorized by its most serious sentence (in the order listed below). One individual could have multiple cases, and each of those cases could result in a sentence.

Prison: A sentence to the Illinois Department of Corrections.

Jail: A sentence to local incarceration in the Cook County Jail, which is administered by the Cook County Sheriff, with or without an accompanying sentence to probation.

Probation: A sentence to supervision of a defendant involving standard terms and conditions, as well as special conditions imposed by a court, served in the community.

Fines: A fixed monetary sanction imposed by a judge based on the severity of the crime committed.

Demographics

Age: Defendant age is calculated at the time the case is filed.

Gender: For cases filed, gender is defined as determined by law enforcement in the following categories: Male, Female, Other/Missing. For individuals admitted to the jail, gender is defined by the Cook County Sheriff's Office in the following categories: Male, Female, Transgender/Non-Binary/Gender Non-Conforming.

Race: For cases filed, race is defined as the racial/ethnic category as determined by law enforcement in the following categories: Hispanic, Black, Asian, White, and Another Race/Ethnicity. For individuals admitted to the jail, race is defined as the racial/ethnic category as determined by the Cook County Sheriff's Office in the following categories: Hispanic, Black, Asian, White, and Another Race/Ethnicity.

Aligned with a person-centered approach, race and ethnicity are combined across the dashboard. If the individual is identified as Hispanic and White, they are categorized as Hispanic. If the individual’s race is logged as Black, they are categorized as Black regardless of their ethnicity.

Defendants of some race/ethnic groups have very few cases included in the data. To address this, some race/ethnic groups are combined into a single category of 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 Clerk of the Circuit Court of Cook County, the Office of the Chief Judge of Cook County, the Cook County Sheriff's Office, the Cook County State’s Attorney’s Office, the Cook County Public Defender’s Office, the Chicago Police Department, and the Illinois Department of Corrections.

We present data in six sections, summarizing information about different parts of the criminal justice process. In each section we present general trends and an overview of cases and characteristics.

Crime

The dashboard relies on data obtained from the Chicago Police Department’s (CPD) online public data portal to determine incidents reported to and arrests made by CPD. For each incident and arrest, we categorized offenses into general offense types (e.g., person, weapons, property, etc.), Index Offenses (using the FBI's index offense classifications), and domestic violence offenses using the IUCR and offense descriptions provided in the CPD data.

Felony Review

The dashboard relies on data obtained from the Cook County State's Attorney's Office (CCSAO) to determine felony charges referred to the State's Attorney and the decision to approve, reject, or continue for further investigation.

Felony review data were structured so that each row in the dataset represented a defendant/case combination. For each defendant/case combination, the data included the referred charge and the felony review outcome. The raw data included 16 separate felony review outcome types which were then aggregated into the following three categories: Rejected (included the initial outcome(s) of "Rejected"); Approved (included the initial outcome(s) of "Approved", "Charge(S) Approved", "Chief Judge Assignment To Felony Courtroom"); Advice/Cont. Investigation (included the initial outcome(s) of "Advice" and "Continued Investigation"); and Other (included the initial outcome(s) of "Arrest Warrant", "Deputy Override", "Disregard", "Felony Review", "Screen Felony", "Search Warrant", "VICTIM SENSITIVE INT", "Victim Sensitive Interview", "Warr Ord Warr Issued", "Warrant Exex"). For the dashboard, defendant/case combinations with the outcome of "Other" were excluded from the felony review charts.

Court

The dashboard relies on court data obtained from the Clerk of the Circuit Court of Cook County to determine cases filed, release/detention decisions, case outcomes, and sentences imposed.

Court data were structured so that each row in the dataset represented a unique charge for each defendant/case combination. Since cases often involve multiple charges, a procedure was devised to categorize cases according to the “top charge” at case filing. To determine the top charge at case filing, filed charges were first ranked by their detainable status under the Pretrial Fairness Act in the following way: detainable public safety offenses (most serious), detainable domestic violence or violation of an order of protection offense, detainable willful flight offense, non-detainable offense (least serious). We then ranked offenses by offense severity according to the state’s three-part misdemeanor and six-part felony classification system. Filed charges were then classified into five distinct offense types (person, weapons, property, drug, public order/other). The filed charge with the highest detainable status was designated as the initial top charge for analysis purposes. When a case contained two filed charges with the same detainable status but different offense severities, charges were ranked according to offense severity. When a case contained two filed charges with the same detainable status and offense severity but different offense types, charges were ranked according to offense type in the following way: person (most serious), weapons, property, drugs, public order/other (least serious). When a case contained two filed charges with the detainable statue, same offense severity, and the same offense type, charges were allowed to randomly select as the top charge. A similar procedure was used to determine the most serious conviction charge when examining sentences imposed.

Initial analyses of the data indicated that individual defendants were often associated with multiple court cases that had release/detention hearings on the same date. The analyses treated separate cases that involved the same defendant and the same release/detention hearing date as a single case. Since the analyses focused on initial release/detention decision, it also was necessary to identify any defendant/case combinations that overlapped in time in the dataset (e.g., if a defendant had an initial hearing in Case 1 and had a hearing in Case 2 before the disposition of Case 1); in such instances, the release/detention hearing in Case 1 was included as the controlling case.

The dashboard relies on the case outcome as categorized in the raw data. The raw data included nine separate case outcome types which were then aggregated into the following seven categories: Nolle (included the initial outcome(s) of "Nolle"), Dismissed (included the initial outcome(s) of "Administrative Closure", "Dis/FNPC", "SOL"), Not Guilty (included the initial outcome(s) of "Not Guilty"), Guilty (included the initial outcome(s) of "Guilty"), Other (included the initial outcome(s) of "Other"), and Open (included the initial outcome(s) of "Pending" or a missing disposition). For the dashboard, cases with the outcome of "Other" or "Open" were excluded from the case disposition charts.

When a defendant is convicted, each conviction charge has a separate sentence. Since cases often involve multiple charges, a procedure was devised to categorize cases according to the “controlling sentence” at sentencing. To determine the controlling sentence, sentences for individual charges were ranked by their severity in the following way: prison (most serious), jail, probation, other sentence (least serious). For example, if any charge in the case included a prison sentence, the controlling sentence for the case was categorized as "prison;" similarly, if any charge in the case included a jail sentence, the controlling sentence for the case was categorized as "jail." In many instances, defendants received a jail sentence followed by a probation sentence; generally, this was for a short jail stay or as credit for time served in jail; in such instances, the controlling sentence for the case was categorized as "probation." If a defendant was sentenced on two separate cases, the controlling sentence for each case is reported in the dashboard. As such, there may be slight differences between, for example, the total number of prison sentences reported and the total number of people admitted to prison in given year.

Jail

The dashboard relies on jail data obtained from the Cook County Sheriff's Office to determine the admissions to jail, releases from jail, and average daily population of the jail.

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.