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Washington State Institute for Criminal Justice Publications and Presentations
The Development and Validation of the STRONG-R Recidivism Risk Assessment.

Hamilton, Kigerl, Campagna, Barnoski, Lee,  van Wormer, &  Block

This study is one of the first describing the development and creation of the Static Risk Offender Needs Guide – Revised (STRONG-R) . The authors describe how predictive performance was optimized for the risk assessment instrument using a large sample (N = 44,010) of reentering  offenders in Washington State. Findings describe the development and design decisions used to create theWashington State Department of Correction’s recidivism prediction instrument to be implemented in 2016.

Publication Abstract

Appendix I STRONG-R Item Scoring | pdf

Appendix II. Offender Needs Assessment | pdf

‘Swift & Certain’: Hawaii Probation Program Goes National.

Hamilton & van Wormer

Washington is the first state to scale the Hawaii’s HOPE model statewide under Drs. Hamilton and van Wormer’s research and direction. Using the HOPE model as a blueprint is an important next step as van Wormer explains in the article. “Historically, across the country, we roll out these big programs, but we drift back towards punitive models. We need to make sure that staff are adhering to these rules and standards.” Hamilton concurs, “The key is that [the HOPE] model is doing sanctions proportionally. Instead of 30 days you’re doing one to three; we’re finding that three days is just as effective as 30, 60 or 90 days.”

‘Swift & Certain’: Hawaii Probation Program Goes National | Huffington Post link


Criminologist Takes on Regional Justice Reform.

van Wormer

A Washington State University faculty member is steering the first major steps in a comprehensive overhaul of the way Spokane area police, courts, judges and detention centers work together. With this project, van Wormer hopes to set a national example and improve public health.

Criminologist takes on regional justice reform | WSU News link


Customizing Offender Assessment.

Hamilton & van Wormer

Since their seminal work “Psychology of Criminal Conduct”, offender assessment has become a staple of the criminal justice system (Andrews & Bonta, 1994). From arrest to  community supervision, it is nearly inconceivable for an individual to have contact with the criminal justice system and not be assessed for any number of attributes. These attributes may include risks, needs, protective factors, skills, deficits, or responsivity an on a variety of outcomes. Whatever the intent, a risk assessment may be built to suit the needs of an agency. Most agencies are either unaware that instruments can be customized to meet their needs and may have difficulties expressing their needs with regard to potential modifications available. To address this challenge, this paper provides a helpful guide to explore the variety of assessment types and considerations needed when customizing a tool to meet an agency’s needs. Topics covered include:

1. Risks and Needs Assessments
2. Weighting, Norming, and Tailoring
3. Outcome Type and Specificity
4. Narrow vs. Broadband Assessments
5. Special Populations and Overrides
6. Gender Responsivity
7. Most Validated vs. Strength of Validation
8. Software Application
9. Case Management Planning

Customizing offender assessment | pdf


Isolating Modeling Effects in Offender Risk Assessment.

Hamilton, Neuilly, Lee, & Barnoski

Recent evolutions in actuarial research have revealed the potential increased utility of machine learning and data-mining strategies to develop statistical models such as classification/decision-tree analysis and neural networks, which are said to mimic the decision-making of practitioners. The current article compares such actuarial modeling methods with a traditional logistic regression risk-assessment development approach.

Utilizing a large purposive sample of Washington State offenders (N  = 297,600), the current study examines and compares the predictive validity of the currently used Washington State Static Risk Assessment (SRA) instrument to classification tree analysis/random forest and neural network models.

Overall findings varied, being dependent on the outcome of interest, with the best model for each method resulting in AUCs ranging from 0.732 to 0.762. Findings reveal some predictive performance improvements with advanced machine-learning methodologies, yet the logistic regression models demonstrate comparable predictive performance.

The study concluded that while data-mining techniques hold potential for improvements over traditional methods, regression-based models demonstrate comparable, and often improved, prediction performance with noted parsimony and greater interpretability.

Isolating modeling effects in offender risk assessment | Abstract

Removing Release Impediments and Reducing Correctional Costs: Evaluation of Washington State’s Housing Voucher Program.

Hamilton, Kigerl, & Hays

Two correctional motives have intertwined in recent years, the desire to reduce incarceration in the United States and the fiscal constraints impacting correctional systems. Simple, evidence-based practices that are focused on rehabilitation and reentry have increased in popularity and have been broadly implemented in a joint effort to reduce reentry issues associated with recidivism and correctional costs. Homelessness is a persistent problem facing prisoners returning to the community. Many inmates were homeless prior to their incarceration, and often return to homelessness after release. The Washington State Department of Corrections’ Housing Voucher Program (HVP) is a reentry program that pays a returning offender’s rent expenses in private housing for up to three months following release. The current study provides an impact evaluation and cost assessment of HVP. Findings demonstrate support for the program and indicate dramatic reductions in associated correctional costs.

Removing Release Impediments: Evaluation of Washington State’s Housing Voucher Program | Abstract

Homelessness and Reentry: A Multisite Outcome Evaluation of Washington State’s Reentry Housing Program for High Risk Offenders.

Lutze, Rosky, & Hamilton

Nearly 700,000 offenders are released from prisons each year in the United States. Many of these offenders are released homeless and are at great risk of being returned to prison. To reduce the likelihood of recidivism, Washington State implemented the Reentry Housing Pilot Program (RHPP) in 2008 to provide housing assistance for up to one year to high risk/high need offenders leaving prisons without a viable place to live. This study provides a multisite outcome evaluation that considers how ex-offenders in the RHPP program, who were provided housing and wrap around services, compare to offenders who were released to homelessness, unstable housing, or stable housing while being traditionally supervised. The findings show that the RHPP program was successful in significantly reducing new convictions, revocations due to technical violations, and readmission to prison for new crimes. The authors recommend that subsidized housing for high risk offenders become a central part of coordinated responses to reentry.

Homelessness and Reentry: A Multisite Outcome Evaluation of Washington State’s Reentry Housing Program for High Risk Offenders | Abstract

The Impact of Transfers Between Prisons on Inmate Misconduct:Testing Importation, Deprivation, and Transfer Theory Models.

Kigerl & Hamilton

The purpose of the present study was to propose and evaluate a new theory on inmate misconduct. Existing research has focused on whether importation characteristics (that describe inmates before admission to prison) and deprivation characteristics (the prison itself) influence misconduct. However, these theories do not account for inmate transfers between prisons. We formulate a new theory of inmate misconduct, termed transportation theory. Specifically, we examine whether or not characteristics of the preceding institution during a transfer influence misconduct in the receiving institution. A sample of 5,926 inmates transferred among 13 Washington State prisons was created to test the effects of importation, deprivation, and transportation theories. The results confirmed prior research indicating offender characteristics and institutional characteristics of the current facility influence misconduct. In addition, support was found for the new theory of transportation, predicting higher levels of misconduct for inmates transferred from larger institutions with higher infraction rates and to institutions with a different custody rating. The findings have implications for security when deciding to transfer inmates, as administrators must consider risk associated with where inmates are sent from as well as where they are sent.

The Impact of Transfers Between Prisons on Inmate Misconduct: Testing Importation, Deprivation, and Transfer Theory Models | Abstract

Triaging Psychiatric


Interview on Spokane Public Radio
February 17, 2014

Dr. Zachary Hamilton speaks concerning research to help reduce recidivism amongst prisoners by matching offenders with treatment programs that prove effective.

Dr. Zachary Hamilton’s presentation* to the Senate
Senate Human Services & Corrections Committee
January 16, 2014

Work Session: Department of Corrections reports to the Legislature, Prison capacity with the Department of Corrections: Overview of capacity and current populations, Justice reinvestment, Report on the Risk Needs Responsivity Project, Status of community
* Dr. Hamilton’s presentation begins at 55:30