"The number of people incarcerated in the United States has increased significantly over the past three decades from approximately 419,000 inmates in 1983 to approximately 1.5 million inmates in 2013. Concerns about both the economic and social consequences of the country's growing reliance on incarceration have led to calls for reforms to the nation's criminal justice system. […] Risk and needs assessment instruments typically consist of a series of items used to collect data on behaviors and attitudes that research indicates are related to the risk of recidivism. Generally, inmates are classified as being high, moderate, or low risk. Assessment instruments are comprised of static and dynamic risk factors. Static risk factors do not change, while dynamic risk factors can either change on their own or be changed through an intervention. In general, research suggests that the most commonly used assessment instruments can, with a moderate level of accuracy, predict who is at risk for violent recidivism. It also suggests that no single instrument is superior to any other when it comes to predictive validity. The Risk-Needs-Responsivity (RNR) model has become the dominant paradigm in risk and needs assessment. The risk principle states that high-risk offenders need to be placed in programs that provide more intensive treatment and services while low-risk offenders should receive minimal or even no intervention. The need principle states that effective treatment should focus on addressing needs that contribute to criminal behavior. The responsivity principle states that rehabilitative programming should be delivered in a style and mode that is consistent with the ability and learning style of the offender."
CRS Report for Congress, R44087