Using descriptive statistics to analyze trends gives a very broad picture of changes in crime and punishment over time. This analysis compares descriptive statistics with legislative actions that changed sentences for unlawful use of weapon offenses. More complex statistical analysis and hypothesis testing would be needed to establish causal relationships between policy actions and changes in crime, incarceration, or recidivism rates over time. In order to verify a causal relationship the study would have to control for a variety of key factors by examining data from economic, public health, education, and other sectors.
Sentencing policy is often driven by high-profile, extreme cases, but most of the offenders we incarcerate are not extreme cases. To focus the discussion on the “Average Joe,” SPAC utilized several data sources to create these snapshots of average offenders in several offense categories.
These snapshots have no predictive value. These snapshots are not meant to affect decisions in individual cases. In each category there are people who fall outside the average profile. Nonetheless, the recurring themes in terms of race, educational attainment, and recidivism are important for understanding broad outcomes of our sentencing policies. SPAC offers these profiles to stimulate the discussion of how we are using incarceration and what we want our prison system to accomplish.
These pie charts illustrate that while low level felonies account for a high number of admissions and exits, they do not remain in the IDOC population long enough per conviction to be a driver of the total population.
The larger the figure, the longer the average stay and the greater the magnitude of resources used. The figures are scaled to the violent Class 1 offenders’ length of stay, meaning First Degree Murder offenders take 5.2 times as many resources as violent Class 1 offenders and nonviolent Class 4 offenders take 1/10th as many resources.
To illustrate how different offense classes consume resources, SPAC analyzed the data for the average number of exits in each class for 2011, 2012 and 2013. Each figure represents 100 offenders. Resources consumed are expressed in bedyears and dollars. The per capita cost for housing one inmate for one year is $21,600, which was multiplied by the bedyears consumed by the entire offense class.
Over the past 22 years, the impact on Illinois’ prison admissions and population of those on Mandatory Supervised Release (MSR) returned to prison as technical violators or with new prison sentences has varied considerably.
Under Illinois' sentencing structure, the majority of those convicted of a felony can be sentenced to either supervision in the community under probation or a period of incarceration within Illinois’ prison system.
The length of time individuals serve in prison is affected by several factors, including changes in the legal classification of crimes and the sentences available for those crimes, pretrial detention practices, prosecutorial charging and plea decisions, judicial sentencing decisions, and policies and practices that impact the ability of correctional administrators to award good conduct and other sentencing credits.