Zachary Hamilton

• Doctor of Philosophy
• Managing Director at Washington State University

The Risk-Needs-Responsivity (RNR) model posits separating lower from higher-risk individuals to avoid “risk contamination.” In a prison setting, policies and restrictions lead to mixing different populations within a housing unit. While this may pose a threat, it may allow higher-risk individuals to gradually promote through security levels, reduci...

In the assessment world, risk determines “who” to treat and needs determine “what” (Bonta & Andrews, 2016). Yet, for youth, greater emphasis is placed on needs that target recidivism reduction interventions. Unlike risk, needs represent dynamic domains, or latent constructs, requiring testing to assure adequate measurement. We conducted a multi-lev...

An abundance of research has established Adverse Childhood Experiences’ (ACEs’) contributions to deviant behavior. Recently, studies have demonstrated the importance of Positive Childhood Experiences (PCEs). Yet, the PCE establishment as a predictive scale is needed. In a multistate, robust sample (N = 254,874) of justice-involved youth, we examine...

Purpose Risk assessments have been constructed using a variety of algorithms, from bivariate associations, to regression, to advanced machine learning (ML) approaches. While promising greater accuracy, agencies are hesitant to adopt tools using newer ML approaches, noting concerns of bias and transparency. Research is needed to identify optimal sce...

Evidence-based interventions have been implemented within penal institutions to reduce the propensity of postrelease reoffending across states. Traditional program evaluations explore these interventions and demonstrate treatment effects most often for a single specific intervention. Although this process supports the doctrine of evidence-based res...

Since their seminal work, Andrews and Bonta outlined the Central Eight assessment domains. As the landscape and utility of criminal justice assessments extended, tool developers expanded upon their initial development principles searching to further risk prediction gains. However, often overlooked in recent advancements is the foundation and usage...

In December 2018, the First Step Act of 2018 was signed into law, which required the Federal Bureau of Prisons (BOP) to begin using risk and needs assessment to assign programs and provide inmates with required treatment. The Attorney General was tasked to develop an assessment to assess and assign inmates to four possible risk levels. In response,...

In most states and jurisdictions, risk assessments are incorporated into justice system practice. Despite decades of use, the methods of tool development are rarely translated to the field. Many agencies implement ‘off-the-shelf’ versions, where a tool developed with a unique set of methods and subjects demonstrates prediction shrinkage when applie...

A number of studies find that solitary confinement is associated with mental impairment. Yet, confinement dosage and which individual and exogenous variables lead to mental impairment have received less attention. This study of 2 years of data on disciplinary segregation male inmates employs a repeated measures design to examine how isolation affec...

Disciplinary segregation (DS) is practiced in a variety of correctional settings and a growing body of research explores its subsequent effects among offenders. The present study contributes to this literature by analyzing the impact of short-term DS on violent infractions and community recidivism among a sample of inmates in Washington State. We a...

The Positive Achievement Change Tool (PACT) was developed in 1997 using a theoretical construction of items, responses, and weights. While derived from an original tool created for a Washington State probation population, the risk-need assessment is one of the most widely used youth tools utilized today. To advance the model from its theoretical co...

Risk assessments have become prevalent in the juvenile justice field. Many of these tools are adopted off-the-shelf and not adapted to fit the characteristics of a jurisdiction’s justice-involved youth. We examined the Positive Achievement Change Tool (PACT) in Iowa. Although used widely, the PACT is relatively unmodified. We updated the tool via i...

As policy makers require more detail justifying rehabilitation expenditures , officials must take inventory on available programming and extant evidence. Unfortunately, little research can be drawn from to aid contextualizing and guiding this process. Using one state example, we report a legislative proviso which sought to investigate current and f...

Risk assessment is now standard practice in corrections and the information produced by these tools informs practitioners at various stages of decision-making. Despite their widespread use, the output from these tools lacks standardization and consistency across assessments and jurisdictions. National efforts are underway to establish best practice...

Provides comprehensive coverage on recidivism risk/needs assessment tools. Correctional and healthcare professionals around the world utilize structured instruments referred to as risk/needs assessment tools to predict the likelihood that an offender will recidivate. Such tools have been found to provide accurate and reliable evaluations and are wi...

The STRONG-R was developed to assess offenders' needs and predict recidivism. The purpose of this chapter was to describe the validity and reliability of the Static Risk Offender Needs Guide – Revised (STRONG-R). Methods and results of our examinations of the instrument's latent structure, inter-rater reliability, and multiple types of validity are...

Creating offender typologies has become a growing interest and a potential method of improving understanding of programming needs and potential placements. Most typological research has only explored and described potential offender types. Relatively few studies have attempted to confirm the existence of created typologies or examine how offenders...

As U.S. correctional systems continue to rollout evidence-based programs, the utility of “complimentary” programs that do not address recidivism reduction remains in question. Many U.S. prisons have a variety of prison-based animal programs, yet the outcomes are largely unexplored. This research addresses a literature gap by evaluating the intermed...

Given that sex offenders have been found to serve longer prison terms compared with other types of violent criminals, it has been suggested that the influence of imprisonment may impact subsequent reoffending. However, institutional factors are often overlooked in risk assessment studies and very few risk assessment instruments include institutiona...

The development of risk–needs assessments has substantially expanded assessment content, which is reflected in the now regular use of both static and dynamic items. However, while the risk–need–responsivity model differentiates between risks and needs theoretically, the scoring of risks and needs does not make for a clear demarcation. We argue that...

Research Summary In the wake of the mass incarceration movement, many states must now manage the rebound of decarceration. Thermodynamic forces of the justice system, however, have pushed former fiscal pressures of institutions onto that of community corrections. Encouraged by the positive findings of recently piloted innovations, several jurisdict...

There is a growing need in Washington to triage patients being considered for inpatient treatment. There has previously been no risk assessment normed to persons with mental illness in the State of Washington. The Static Risk Assessment (SRA) is used in Washington to assess risk among offenders under State Department of Corrections supervision. The...

A brief discussion of offender risk and needs assessment and the methods and options in which they may be customized for specific jurisdiction needs.

The purpose of this study is to propose and test a new theory of prisoner misconduct. Research has focused on influences of misconduct that originate from the community (importation) or that originate from the prison environment itself (deprivation). We formulate a new theory of misconduct, transfer theory. Transfer theory posits that influences of...

Recidivism risk assessment tools have been utilized for decades. Although their implementation and use have the potential to touch nearly every aspect of the correctional system, the creation and examination of optimal development methods have been restricted to a small group of instrument developers. Furthermore, the methodological variation among...

While social support theory has been applied to a variety of criminal justice settings, there has been little empirical research on the effect of social support on inmate behavior. In this article, we test Cullen’s proposition that social support, in whatever form it manifests itself, has an effect on Korean inmates’ experiences. Specifically, we e...

Halfway houses (HWHs) are one resource that the New Jersey DOC utilizes to transition offenders from prison back into society. Previous studies show that offenders who participated in HWH programming are at less risk for recidivating compared to nonparticipants (Austin, 20014. Austin, J. (2001). Prisoner reentry: current trends, practices, and issu...

Halfway houses (HWHs) are a common intervention for substance-abusing offenders. Facilities utilized to provide treatment for correctional populations are typically privately managed, often leading to variations in amounts and types of services and treatments. This study examines recidivism outcomes of substance-abusing offenders receiving halfway...

Despite the nationwide use of halfway houses (HWHs), empirical findings documenting their impact have been generally infrequent over the last 30 years. Recent high-profile incidents have increased public attention and raised questions regarding their effectiveness and appropriate use. In response, this study provides information needed to fill the...

Objectives 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 mod...

Homelessness is a persistent problem facing offenders returning to the community from prison. Many offenders were homeless prior to incarceration, and often return to homelessness after release. Additionally, the costs of incarceration have led policy-makers to consider large-scale alternatives to rapidly and effectively reduce correctional costs....

The purpose of the present meta-analysis was to answer the question: Can the Andrews principles of risk, needs, and responsivity, originally developed for programs that treat offenders, be extended to programs that treat drug abusers? Drawing from a dataset that included 243 independent comparisons, we conducted random-effects meta-regression and A...

This article presents the results of a meta-analysis of the existing research literature, in an effort to increase our understanding of the prevalence of domestic violence (DV) among pregnant women, and of risk factors associated with DV during pregnancy. Across 92 independent studies, the average reported prevalence of emotional abuse was 28.4%, p...

Each year many offenders are released homeless putting them at great risk of being returned to prison. To reduce the likelihood of recidivism, Washington State implemented the Reentry Housing Pilot Program (RHPP) to provide housing assistance for high risk/high need offenders leaving prison without a viable place to live. This study provides a long...

Given recent fiscal issues and the continual struggle to reduce the nation’s overuse of incarceration, a renewed focus has been placed on the efforts of community corrections and alternative sanctions. Halfway houses represent a common and, until recently, infrequently evaluated intervention for inmates returning to the community. Although the mode...

This random assignment study compared female offenders (n = 468) with substance use disorders in a prison therapeutic community program with those in a cognitive-behavioral intervention. The study demonstrates that all women benefitted from gender-sensitive prison treatment, but the therapeutic community was more effective in reducing drug use, cri...

Of the 13 principles of drug addiction treatment disseminated by the National Institute on Drug Abuse (NIDA), 7 were meta-analyzed as part of the Evidence-based Principles of Treatment (EPT) project. By averaging outcomes over the diverse programs included in the EPT, we found that 5 of the NIDA principles examined are supported: matching treatment...

The reentry court model was created to address the risks and needs of offenders returning to the community during the period immediately following release. While there is growing interest in reentry courts, research to date has been limited. This study utilized a quasi-experimental design, comparing reentry court participants with traditional parol...

This study examined the relationships between substance abuse, mental health problems and HIV risk behavior in offenders discharged from prison and referred to substance abuse treatment programs. Data from 34 sites (n = 1,358) in a federally-funded cooperative agreement, the Criminal Justice Drug Abuse Treatment Studies (CJDATS), were analyzed. Amo...

This article describes a study that examined the relationship between multiple Axis I mental health diagnoses and treatment outcomes for female offenders in prison substance abuse treatment programs. Preliminary findings of the effectiveness of therapeutic community (TC) treatment, modified for female offenders, relative to a control cognitive beha...

This study examines the relationship between psychiatric symptoms and violent/disruptive behavior among 192 inmates who participated in prison-based substance abuse treatment. Participants came from two sites able to provide narrative reports of disciplinary actions in the Criminal Justice Drug Abuse Treatment Studies' Co-Occurring Disorders Screen...

This random assignment study compared women in a prison Therapeutic Community (TC) program with those in a cognitive-behavioral intervention. Over two thirds of study subjects received a lifetime diagnosis of severe mental disorder, nearly one-half received a diagnosis of PTSD, and virtually all reported exposure to trauma. Preliminary analysis (n...

The Evidence-based Principles of Treatment (EPT) project is conducting meta-analytic research on drug abuse treatment studies to assess whether some of the National Institute on Drug Abuse's (1999) recommended "Principles of Drug Addiction Treatment are supported by empirical research over the past thirty years. NIDA's Principle 3 is that effective...

Data on 2,303 youth participating in the New York State Mental Health/ Juvenile Justice Diversion Program were used to explore differences between girls and boys on factors commonly associated with two juvenile justice outcomes: recidivism and out-of-community placement. Bivariate analyses reveal predictable differences between justice-involved gir...

For a number of reasons, researchers and policy makers are now focusing on diversion of youth from the juvenile justice system. This study examines New York State's diversion efforts focused on youth with mental health and substance abuse problems who are at risk of out-of-community placement (N = 2,309). Twelve counties participated in the Mental...

Empirically, one of the most consistently observed correlations in social science inquiry is that of substance use and criminal behavior. Recently, these behaviors have been examined separately within longitudinal, career-based frameworks. This study assesses the joint distribution of crime and substance use over several years and identifies a numb...

In the U.S., diversion has increasingly become one of the most utilized alternatives to detention of delinquent youth. Programs providing diversion can vary greatly. Variations in program design make it difficult to evaluate the effectiveness of program outcomes. Utilizing hierarchical linear modeling, this study examines variations in outcome for...

As part of an effort to improve services and outcomes for women with histories of trauma and co-occurring mental health and substance abuse disorders, the Franklin County Women and Violence Project sought to assess women's perceptions about their social roles and provide them with opportunities to adopt valued social roles. Social role theory sugge...

As part of an effort to improve services and outcomes for women with histories of trauma and co-occurring mental health and substance abuse disorders, the Franklin County Women and Violence Project sought to assess women's perceptions about their social roles and provide them with opportunities to adopt valued social roles. Social role theory sugge...