Sonja Siennick studies criminal offending and mental health problems in the contexts of the life course and kinship and friendship relations. Her recent publications have examined ways to mitigate the collateral consequences of criminal justice system contacts. A current project, funded by the National Institute of Justice, tests the efficacy of a focused deterrence intervention in reducing firearm recidivism among youth. Past funded projects have examined the unique features of school violence as compared with other forms of juvenile offending, the prevalence and predictors of officially detected recidivism among juveniles, the association of solitary confinement with mental health, substance use and peer problems among adolescents with depression, and the effectiveness of a school-based intervention for justice system–involved adolescents.
Crime and Deviance | Mental Health | Kinship and Friendship Relations | Life Course | Quantitative Methods
PhD. 2009, The Pennsylvania State University; Sociology
M.A. 2005, The Pennsylvania State University; Crime, Law, and Justice
B.A. 2001, Purchase College, State University of New York; Psychology
“Focused Deterrence among Juveniles: A Multicenter Randomized Controlled Trial Study of Effects and Mechanisms.” Co-Principal Investigator. National Institute of Justice, 2025-2029.
“A Mixed-Methods Examination of the Unique Root Causes of School Violence.” Co-Principal Investigator. National Institute of Justice, 2022-2024.
“A Two-State Examination of Varied Measurement Strategies for Reoffending.” Principal Investigator. National Institute of Justice, 2021-2023.
“The Impacts of Restrictive Housing on Inmate Behavior, Mental Health, and Recidivism, and Prison Systems and Personnel.” Research Advisor and Lead Analyst. National Institute of Justice, 2017-2019.
“The Palm Beach County School Safety and Student Performance Partnership Research Project.” Co-Principal Investigator of subcontract to Florida State University. National Institute of Justice, 2014-2018.
“Adolescent Friendship Networks and the Emergence of Substance Use.” Co-Investigator. National Institute on Drug Abuse, 2013-2018.
Siennick, Sonja E., and Lauren C. Porter. Forthcoming. Who succeeds? A review of theory and research on the moderators of post-incarceration outcomes. Annual Review of Criminology.
Siennick, Sonja E., and Alex O. Widdowson. 2025. Do short spells matter? Conceptualizing and testing the effects of brief incarcerations on labor market outcomes. Journal of Research in Crime and Delinquency 62(6): 856-899.
Siennick, Sonja E., Alex O. Widdowson, Brian J. Stults, and Julie Kuper. 2025. Explaining inconsistencies in the effects of incarceration on socioeconomic attainment: The role of parental co-residence. Journal of Research in Crime and Delinquency 62(5): 744-771.
*Talaugon, Alyssa, Jillian J. Turanovic, and Sonja E. Siennick. Forthcoming. The consequences of victimization for suspension: Specifying a pathway through school problem behaviors in early adolescence. Journal of School Violence.
Siennick, Sonja E., Daniel P. Mears, and *Alyssa Spies. 2024. The use of restrictive housing with incarcerated persons with mental illness: Variation in placement disparities by restrictive housing type. Journal of Criminal Justice 95, Article 102311.
Siennick, Sonja E., *Jhon A. Pupo, William M. Casey, *Dequan Cowell, and Brian J. Stults. 2024. Does measurement matter? Examining the impact of outcome measurement variation on the rates and predictors of juvenile recidivism. American Journal of Criminal Justice 49: 653-677.
Siennick, Sonja E., and Jillian J. Turanovic. 2024. The longitudinal associations between bullying involvement and internalizing symptoms: Bidirectionality and mediation by friend support. Development and Psychopathology 36(2): 866-877.
Siennick, Sonja E., and Lauren C. Porter. Forthcoming. Who succeeds? A review of theory and research on the moderators of post-incarceration outcomes. Annual Review of Criminology.
Siennick, Sonja E., and Alex O. Widdowson. 2025. Do short spells matter? Conceptualizing and testing the effects of brief incarcerations on labor market outcomes. Journal of Research in Crime and Delinquency 62(6): 856-899.
Siennick, Sonja E., Alex O. Widdowson, Brian J. Stults, and Julie Kuper. 2025. Explaining inconsistencies in the effects of incarceration on socioeconomic attainment: The role of parental co-residence. Journal of Research in Crime and Delinquency 62(5): 744-771.
Siennick, Sonja E., Mayra Picon, Jennifer M. Brown, and Daniel P. Mears. 2022. Revisiting and unpacking the mental illness and solitary confinement relationship. Justice Quarterly 39(4): 772-801.
Siennick, Sonja E., and Alex O. Widdowson. 2022. Juvenile arrest and later economic attainment: Strength and mechanisms of the relationship. Journal of Quantitative Criminology 38: 23-50.
Mears, Daniel P., Jennifer M. Brown*, Joshua C. Cochran, and Sonja E. Siennick. 2021. Extended solitary confinement for managing prison systems: Placement disparities and their implications. Justice Quarterly 38(7): 1492-1518.
Widdowson, Alex O., Carter Hay, and Sonja E. Siennick. 2021. Romantic partners and young adult offending: Considering the role of partner’s socioeconomic characteristics. Criminology 59: 158-190.
Widdowson, Alex O., and Sonja E. Siennick. 2021. Residential mobility and desistance from crime during the transition to adulthood. Journal of Research in Crime and Delinquency 58(2): 151-191.
Widdowson, Alex O., Wade C. Jacobsen, Sonja E. Siennick, and Patricia Y. Warren. 2020. Together despite the odds: Explaining racial and ethnic heterogeneity in relationship dissolution following incarceration. Criminology 58(1): 129-155.