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Robert John Zagar (born c. 1948) is a professor at Chicago School of Professional Psychology working in forensic neuropsychology. He is noted for his work in methodology and research design regarding the prediction and prevention of violence, specifically improving the sensitivity and the specificity of measuring the potential for violence, changing policy regarding high risk teens, and reducing the number of nonviolent offenders in jail.
Zagar was born in 1948 at Great Lakes Navy Base. He completed his undergraduate education in psychology at the University of Wisconsin Milwaukee and earned a master’s from Illinois Institute of Technology. Zagar earned a doctorate in research design and statistics from Northwestern University and completed a postdoctoral fellowship at Rush University Medical College at the Sleep Disorder Center. During a second postdoctoral fellowship at the University of Illinois at Chicago Health Sciences Center, he earned a master's degree in public health. Zagar taught at Argosy University, Barry University, DePaul University, Lewis University, Loyola University, Northwestern University, University of Illinois at Chicago, the Chicago, Illinois and Forest Schools of Professional Psychology, and Calumet College of Saint Joseph. He testified before the U.S. House of Representatives Judiciary Subcommittee on Crime Terrorism and Homeland Security on 24 July 2012 about the improved accuracy and precision of a model for predicting violence that saved the lives and expenses by targeting high risk teens with evidence based diversions of jobs, mentors and anger management. Chicago Mayor Richard Daley shared Zagar’s “Predicting and Preventing Homicide A Cost Effective Empirical Approach from Infancy to Adulthood,” with the University of Chicago that founded a Crime Laboratory to impact on Chicago city policy to lower violence. President Clinton thought Zagar’s work was “convincing and persuasive.” and shared the research and its application to the US Attorney General. President Obama followed in the footsteps of Cook County President Preckwinkle who released 56% of nonviolent offenders starting in September 2011 without recidivism after reading Zagar’s “Predicting and Preventing Homicide.” Obama released 6,800 nonviolent federal offenders by commutation and pardon in 2015 and 2016. Zagar's work impacted on the U.S. Supreme Court in Graham v. Florida and Miller v. Alabama in 2,500 juveniles with life sentences without parole who must be re-sentenced. Zagar showed that juvenile murderers do not have the decision making capacities that adults do. Zagar served on the Committee on Clergy Abuse for Archdiocese of Chicago and Youth Violence for the American Psychological Association. He and his wife, Agata, founded a nonprofit organization Society of the Friends of Radgoszcz to benefit youth in Central Europe.
Zagar made contributions that impact a wide range of disciplines, namely prevention of violence and its cost by affecting policy and prediction of violence. According to the editors of Psychological Reports, “The implications of these complex data are important for fields as diverse as psychology, physiology, economics, and criminology and are of interest to business, human resources, and the police and military.” The major focus of his work was the nondiscriminatory, objective, reliable, sensitive, specific and valid study of the prediction of violence and the application of evidence based diversions to prevent violence namely deaths and the costs associated with it.
Zagar developed a model of violence from infancy to adulthood for males and females based on data collected at the “first” juvenile court founded in 1899, the Juvenile Division Cook County Circuit Court of Cook County. According to the Editors of Psychological Reports, “Zagar and colleagues' five studies used random sampling and individually matched controls, with large samples of the most at-risk youth and violent delinquents and adults. This was achieved by oversampling the highest risk groups, abused infants and children and violent youth and adults, in an area representative of those where most homicides occur. Data for these individuals were gathered from court, medical, school, and other records and include virtually all known risks for delinquency. Quasi-experimental design and the use of robust modern statistical techniques yielded a detailed picture of risks in abused and violent youth and their comparison groups, which were strongly differentiated with accuracies of 78 to 99%. The implications are wide-ranging, since with increased accuracy of predicting violence and homicide, there is less chance of false positives (e.g., unnecessary incarceration) and false negatives (e.g., release of dangerous offenders).”
According to Loyola University of Chicago Maude C. Clark Professor of Humanistic Psychology and former Director Life Development Center, Cornell University, James Garbarino, Zagar found “the characteristics that increase the risk of a teenager committing homicide are: coming from a family with a history of violence; being abused; belonging to a gang; abusing alcohol and drugs; using a weapon; being arrested; having a neurological illness; and having issues at school including attendance. Odds of homicide increase as the number of risk factors increase. This is a general principle in understanding human development…. The risk factors that Robert Zagar and his colleagues identified in 1990 as correlated with a boy’s chances of committing murder continue to increase.”
Clinical Professor of Psychiatry at Georgetown University Medical School and editor of International Annals of Psychiatry, Alan Z. Schwartzburg M.D. noted that “Robert Zagar and his colleagues present an extensive controlled study of adolescents who kill ... who had high rates of medical risks factors such as abuse, injuries, mental retardation, hyperactivity, membership in criminal violent families, aggressive behavior in childhood, alcoholism, polysubstance abuse, school failure. They focus on the implications of the study for preventive strategies for high risk individuals such as early identification of high risk children and families, access to early medical care, and integration of approaches to the high risk adolescent by increased cooperation among physicians, schools, families, government and law enforcement agencies.”
Preventing Violence: Public Policy
Zagar worked on changing policy regarding high risk teens by influencing Chicago Mayor Richard Daley to target at risk youth diverting them from violence with jobs, mentors and anger management in a program called “Culture of Calm” funded by the $78,000,000 U.S. Department of Justice saving lives and expenses. This was continued under Chicago Mayor Emanuel in a new $50,000,000 Chicago Public Safety Fund program labelled “Get In” and “Summer Plus One.” Garbarino said “by intervening to divert high risk youths from this predictable pathway, lives and money could be saved. In Chicago, a program that invested in jobs, mentoring and anger management resulted in a 46% reduction in the number of shootings and a 77% drop in the number of assaults (compared to what would have occurred if the investment were not made in the kids identified by Zagar’s predictive model). Where can the money for such preventive efforts come from? The cost-benefit analysis presented in Zagar’s research offers one clear answer: for every dollar invested in diverting a high risk kid from the pathway that leads to murder, more than six dollars are saved in future monetary costs associated with killing.”
Predicting Violence: An Actuarial Approach
Zagar developed a test to measure abuse and aggression among adults and adolescents named the Standard Predictor of Violence Potential. According to Professor Garbarino “Zagar and Grove improved the accuracy of predicting homicide from records of up to 12 years of early childhood and youth risks in a sample of 1,127 youths to 91% (as expressed as “Area under the Curve [AUC] = .91”). Using a similar procedure, among 1,595 adults, using Shao’s bootstrapped logistic regression procedure, the predictive power was 99%. The predictive equations in a combined adult and youth sample of 2,722 were correct 97% of the time. The accuracy of these results is noteworthy because most literature attempting to predict recidivism or violence has been in the region of 69% to 76%. Thus, the bootstrapped logistic regression represents a considerable improvement in predictive accuracy, providing a sound empirical basis for risks that consistently and reliably predict future violent criminal activity.” Garbarino goes on, “For improvement on this success rate, we can look to the work of Chicago psychologist Robert Zagar and his colleagues. Zagar has worked for more than twenty years with the Cook County Court in an effort to understand how violence arises in the city, how to predict which individuals are most likely to act violently, how to figure out which inmates are most likely to become repeat offenders if release, and how to prevent early risk factors from translating into violent delinquent behavior in the first place. It’s very important work. The key to Zagar’s work has been developing a mathematical formula (an “actuarial model”) for predicting which of the many kids “at risk” will actually end up killing someone (as well as predictions regarding sexual assault). Using a mix of psychological tests (the 823 item online version takes about 2 hours to complete) and records from social-service and health agencies as well as the courts, Zagar and his colleagues have come up with a statistical “actuarial” approach that is remarkably accurate. The model identifies 97% of those who end up as killers (missing only 3%), and it misidentifies as killers only 3% of those who do not end up killing anyone. Thus, in statistical terms, this approach offers excellent “sensitivity” (also called “true positive rate” because it represents the proportion of the actual positives that the model correctly identified as such-i.e., the 97% of the killers who were correctly classified as such). And it offers excellent specificity (also called the “true negative rate” – the 97% of the non-offenders who are correctly classified as such). It is extremely hard to achieve such high rates of sensitivity and specificity at the same time, so this is a major achievement. It validates what I have been saying. These are the factors in their formula: prior court contact(s) or arrests; poor executive functioning (decision making and related abilities); lower social maturity; weapon possession conviction; violent family; gang membership or participation; male; academic underachievement; serious illnesses; low socioeconomic status; substance abuse; previous neurological disorder; alcohol abuse; head injury; truancy/suspension or expulsion; single parent family or orphaned; hyperactivity; epilepsy and other illnesses; unemployment; antisocial personality; and physical abuse.”
- Busch, K. G., Zagar, Robert J., Grove, William.M., Hughes, John Russell, Arbit, J., Bussell, R. E. & Bartikowski, B. (2009). "Looking forward in records of young adults convicted of sexual homicide, rape or molestation as youth: Risks for re-offending". Psychological Reports, doi: 104, 155-184.
- Hughes, John Russell., Zagar, Robert J., Busch, Kenneth G., Grove, William M. (2009). "Looking forward in records of youth abused as children: risks for homicidal, violent and delinquent offenses". Psychological Reports, 104, 77-102. doi: 10.2466/PR0.104.1.17-45
- Zagar, Robert John. (2009) "Identification, treatment and prevention of homicide: fallacies in research, treatment, and policy – a postscript on youth violence. Psychological Reports", Psychological Reports doi: 10.2466/PR0.104.1.363-377
- Zagar, Robert John., Busch, Kenneth G., Grove, William M. Hughes, John Russell. (2009). "Summary of studies of abused infants and children later homicidal, homicidal, assaulting later homicidal and sexual homicidal youth and adults." Psychological Reports, 104, 17-46 doi: 10.2466/PR0.104.1.17-45
- Zagar, Robert John., Busch, Kenneth G., Grove, W. M., Hughes, John Russell, Arbit, J. (2009). "Looking forward in records of youth abused as infants: Risks for homicidal, violent, and delinquent offenses". Psychological Reports, 104, 47-76. doi: 10.2466/PR0.104.1.17-45
- Zagar, Robert John., Busch, Kenneth G., Grove, W. M., & Hughes, John Russell. (2009). "Can violent re-offense be predicted? A review of the roles of the clinician and use of actuarial tests in light of new data". Psychological Reports, doi: 104, 247-278. 10.2466/PR0.104.1.247-277
- Zagar, Robert John, Busch, Kenneth G., Grove, William M., Hughes, John Russell, Arbit, J. (2009). "Looking forward and backward in records for risks among homicidal youth". Psychological Reports, 104, 103-128. doi: 10.2466/PR0.104.1.103-127
- Zagar, Robert John, Busch, Kenneth G., Grove, William M., Hughes, John Russell, Arbit, J. (2009). "Looking forward in records of young adults who were convicted of homicide or assault as youth: risks for re-offending". Psychological Reports, 104, 129-154. doi: 10.2466/PR0.104.1.129-154
- Zagar, Robert John., Busch, Kenneth G., Hughes, John Russell. (2009). "Empirical risk factors for delinquency and best treatments: Where do we go from here?" Psychological Reports, 104, 279-308. doi: 10.2466/PR0.104.1.279-308
- Zagar, Robert John., Busch, Kenneth G., Hughes, John Russell, Arbit, J. (2009). "Comparing early and late twentieth century Boston and Chicago male juvenile offenders: what changed?" Psychological Reports, 104, 185-198. doi: 10.2466/PR0.104.1.185-19
- Zagar, R. J., Isbell, S. A., Busch, K. G., & Hughes, J. R. (2009). "An empirical theory of development of homicide within individuals." Psychological Reports, : 104, 199-246.doi: 10.2466/PR0.104.1.199-245
- Zagar, R. J., & Zagar, A. K. (2009). "An introduction to a series of studies on abused, delinquent, violent, and homicidal youth and adults." Psychological Reports, 104, 9-16. doi: 10.2466/PR0.104.1.17-45
- Zagar, A. K., Zagar, R. J., Bartikowski, B., & Busch, K. G. (2009). "Cost comparisons of raising a child from birth to 17 years among samples of abused, delinquent, violent, and homicidal using victimization and justice system estimates." Psychological Reports, 104, 309-338. doi: 10.2466/PR0.104.1.309-338
- Zagar, R. J., Zagar, A. K., Bartikowski, B., Busch, K. G., & Stark, R. (2009). "Accepted legal applications of actuarial testing and delinquency interventions: examples of savings in real life situations." Psychological Reports, 104, 339-362. doi: 10.2466/PR0.104.1.339-362
- Zagar, R. J., Zagar, A. K., Busch, K. G., Garbarino, J., Ferrari, T., Hughes, J. R., Patzer, G., Kovach, J. W., Grove, W. M., Tippins, S., Imgrund, S., Dempsey, J. Q., & Basile, B., (2016). "Finding high risk persons with internet-based tests to manage risk: A literature review with policy implications to avoid tragedies, save lives and money. Review of European Studies.", 8, 1, 1-31.
- Zagar, R. J. (2014). "Practical Solutions to Violence." Association for Psychological Science, October 8
- Zagar, R. J. (1981). Time of day as related to problem solving ability and classroom behavior. Dissertation Abstracts International, June.
- Scott, Bobby (2012). "Youth Promise Act. Violence Prevention Briefing Materials." Video link.
- Teller, K. (2008). "Annual ball of the Society of the Friends of Radgoszcz.", Polish News, May 19, 2008.
- The Editors (2009). "Preface to predicting and preventing homicide: A cost effective empirical approach from infancy to adulthood." Psychological Reports, 104, 5-7. https://dx.doi.org/10.2466/PR0.104.1.3-5.
- Garbarino, J. (1999). Lost boys: why our sons turn violent and how we can save them. New York: Free Press.
- Zagar, R. J., Arbit, J., Busch, K. G., Hughes, J. R. & Sylvies, R. (1998). Juvenile murderers: Are there more medical risks? In Adolescents in turmoil, (Ed.) A. Schwartzberg, Westport, Connecticut: Greenwood. pp. 143–156.
- Zagar, R. J., Grove, W.M., & Busch, K.G. (2013). "Delinquency best treatments: How do we divert youth from crime and save detention costs. Behavior Sciences and the Law.", 31, 381-396. doi: 10.1002/bsl.2062
- Zagar, R. J., Kovach, J., Ferrari, T., Grove, W.M., Busch, K.G., Hughes, J.R., & Zagar, A.K. (2013). "Applying best treatments by using a regression equation to target violent prone at-risk youth: A review." Comprehensive Psychology, 2, 6. 10.2466/03.16.49.CP.2.7
- Garbarino, J. (2015) "Listening to killers; lessons learned from my 20 years as a psychological expert witness." Oakland California: University of San Francisco Press.
- Zagar, R. J., & Grove, W. M. Violence risk appraisal of male and female youth, adults, and individuals. Psychological Reports, 107, 3, 983-1009. https://dx.doi.org.10.2466/02.03.16.PR0.107.6.983-1009
- Zagar, R. J., Kovach, J., Basile, B., Grove, W. M., Hughes, J. R., Busch, K. G., Zablocki, M., Osnowitz, W., Neuhengen, J., Liu, Y., & Zagar, A. K. (2013). "Finding workers, offenders or students most at-risk for violence: actuarial tests save lives and resources." Psychological Reports.113, 685-716. doi: 16.03.PR0.113x29z3
- Shao J. (1996). "Bootstrap model selection. Journal of the American Statistical Association" 91, 655-665.
- Zagar, R. J., Arbit, J., Busch, K. G., Hughes, J. R., & Sylvies, R. (1991). "Homicidal adolescents: a replication. Psychological Reports.", 67, 1235-1242