Death-sentenced prisoners with credible evidence of innocence have gained significant attention this month with the execution of Marcellus Williams in Missouri, the near-execution of Robert Roberson in Texas, and the U.S. Supreme Court arguments in Glossip v. Oklahoma. There is a common misconception that DNA evidence is widely available in all cases and central to exonerations, but the reality is that DNA exonerations in death penalty cases are relatively rare. DPI has identified 34 cases across 15 US states in the modern death penalty era of people who have been exonerated from death row with DNA evidence—with the first case being Kirk Bloodsworth in 1993 (he was convicted in 1985). These numbers represent just 17% of the 200 death row exonerations.
The average time spent on death row by people exonerated thanks to DNA is 18.6 years, for a total across the 24 cases of 631 years spent in prison for crimes they did not commit. Few of these exonerees have been adequately compensated.
The Innocence Project reports 375 DNA exonerations in criminal cases between 1989 and 2020. Before 2000, only a handful of states allowed post-conviction DNA testing. That changed in 2004 with the passage of the Justice for All Act. In her 2020 article, Chi-Hsin Engelhart argues that post-conviction DNA testing is a procedural due process right that should be constitutionally protected. She notes this protection is especially important in the context of death row to explore the potential of wrongful execution, concluding that a denial of access and testing could lead to a violation of the Eighth Amendment. Ms. Engelhart argues that courts should shift their emphasis from finality to accuracy in the legal system, and that allowing for DNA testing in post-conviction proceedings would advance this goal.
During a recent discussion moderated by DPI Executive Director Robin Maher at the French Ambassador’s Residence in Washington, D.C., Vanessa Potkin, Director of Special Litigation at the Innocence Project, noted that DNA evidence is available in less than 10% of crimes. The case of Marcellus “Khaliifah” Williams, who was executed on September 24, 2024, illustrates that even when DNA evidence can be obtained from the crime scene, forensic materials may degrade or become contaminated, rendering them unusable for proving a defendant’s innocence.
Robert DuBoise was wrongfully convicted of murder and sentenced to death in Florida in 1983 based on faulty forensics, including the since-debunked practice of bite mark matching. DNA testing ultimately exonerated him in 2020 and in February 2024, Mr. DuBoise received $14 million compensation for his wrongful conviction.
As scientific and technological progress continues, many prisoners may benefit from these advancements. However, many legal procedural barriers continue to block prisoners from accessing DNA evidence that has the potential to exonerate them.
Albeck-Ripka, L., 2024. Man Wrongfully Imprisoned for 37 Years to Receive $14 Million From City of Tampa. The New York Times.
Aronson, J.D., Cole, S.A., 2009. Science and the Death Penalty: DNA, Innocence, and the Debate over Capital Punishment in the United States. Law & Social Inquiry 34, 603 – 633.
DNA Exonerations in the United States (1989 – 2020), n.d. Innocence Project.
Engelhart, C.-H.E., 2020. Post-Conviction DNA Testing in Death Row: A Constitutional Argument under the Due Process Framework. Cardozo J. Equal Rts. & Soc. Just. 27, 111.
Exoneration by Year, The National Registry of Exonerations, n.d., University of Michigan.
Liebman, J.S., 2001. New Death Penalty Debate: What’s DNA Got to Do with It. Colum. Hum. Rts. L. Rev. 33, 527.
To learn more about how DNA was used in other exoneration cases (not only capital ones), you can visit the National Registry of Exonerations website. Their 2023 data showcase that DNA evidence played a critical but limited role in the broader scope of exonerations, with 24 exonerations last year (164 total).
