Rate of false conviction of criminal defendants who are sentenced to death.
The rate of erroneous conviction of innocent criminal defendants is often described as not merely unknown but unknowable. There is no systematic method to determine the accuracy of a criminal conviction; if there were, these errors would not occur in the first place. As a result, very few false convictions are ever discovered, and those that are discovered are not representative of the group as a whole. In the United States, however, a high proportion of false convictions that do come to light and produce exonerations are concentrated among the tiny minority of cases in which defendants are sentenced to death. This makes it possible to use data on death row exonerations to estimate the overall rate of false conviction among death sentences. The high rate of exoneration among death-sentenced defendants appears to be driven by the threat of execution, but most death-sentenced defendants are removed from death row and resentenced to life imprisonment, after which the likelihood of exoneration drops sharply. We use survival analysis to model this effect, and estimate that if all death-sentenced defendants remained under sentence of death indefinitely, at least 4.1% would be exonerated. We conclude that this is a conservative estimate of the proportion of false conviction among death sentences in the United States.
University of Michigan Law School, Ann Arbor, MI 49109; srgross@umich.edu.
Samuel R
SR
Gross
Michigan State University College of Law, East Lansing, MI 48824;
Barbara
B
O'Brien
American College of Radiology Clinical Research Center, Philadelphia, PA 19103; and.
Chen
C
Hu
Department of Biostatistics and Epidemiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104.
Edward H
EH
Kennedy
D002203:Capital Punishment / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D057237:Criminals; D006708:Homicide; D006801:Humans; D053208:Kaplan-Meier Estimate; D011329:Prisoners; D011330:Prisons; D016019:Survival Analysis; D013997:Time Factors; D014481:United States
capital punishment; criminal justice; wrongful conviction