Estimating the Prevalence of Wrongful Convictions, Virginia, 1973-1987 (ICPSR 36836)

Version Date: Sep 15, 2021 View help for published

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Kelly Walsh, Urban Institute

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This study extends research on wrongful convictions in the United States and the factors associated with justice system errors that lead to the incarceration of innocent people. Among cases where physical evidence produced a DNA profile of known origin, 12.6 percent of the cases had DNA evidence that would support a claim of wrongful conviction. Extrapolating to all cases in our dataset, the investigators estimate a slightly smaller rate of 11.6 percent. This result was based on forensics, case processing, and disposition data collected on murder and sexual assault convictions in the 1970s and 1980s across 56 circuit courts in the state of Virginia. To address limitations in the amount and type of information provided in forensic files that were reviewed in the Urban Institute's prior examination of these data, the current research includes data collected through a review of all publicly available documents on court processes and dispositions across the 714 convictions, which the investigators use to reassess prior estimates of wrongful conviction.

Walsh, Kelly. Estimating the Prevalence of Wrongful Convictions, Virginia, 1973-1987. Inter-university Consortium for Political and Social Research [distributor], 2021-09-15.

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United States Department of Justice. Office of Justice Programs. National Institute of Justice (2013-IJ-CX-0004)


Access to these data is restricted. Users interested in obtaining these data must complete a Restricted Data Use Agreement, specify the reasons for the request, and obtain IRB approval or notice of exemption for their research.

Inter-university Consortium for Political and Social Research

1973 -- 1987
2009-03 -- 2011-08 (Part I), 2014-08 -- 2017-05 (Part II)
  1. The first report from analysis of Part I data (based only on forensic files and not courthouse files) can be found here:


The purpose of this study is to extend prior research on the prevalence of wrongful convictions based on forensics, case processing, and disposition data.

The study design includes two parts. Part I includes the 2012 Urban Institute report, "Post-Conviction DNA Testing and Wrongful Conviction," which presented an estimated rate of wrongful conviction based on post-conviction DNA testing of over 700 felony convictions in the state of Virginia between 1973 and 1987 (Roman et al. 2012). Part II of the study represents an effort to overcome the limitations of the Part I study by reviewing all publicly available files from over 50 Virginia Circuit Courts to collect case processing and disposition data for each conviction included in Part I.

Cases in this study represent 714 murder and/or sexual assault convictions disposed in Virginia between 1973 and 1987 for which forensic evidence from the original case file was found.

Sexual assault and homicide cases where there was a conviction and physical evidence was retained in Virginia between 1973 and 1987.


Variables include whether or not many specific types of forensic evidence were available, details on the case such as plea, type of trial, type of counsel, and others, as well as offender demographic data.

Not available.

Not applicable.



2021-09-15 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Checked for undocumented or out-of-range codes.

The variable Determinate_Weight is an inverse probability weight used to adjust the sample of cases with determinate post-conviction DNA testing results to assimilate all cases involving a sexual assault component (as identified using the variable Court_Sexassault).



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