In testimony before the Massachusetts Joint Committee on the Judiciary regarding proposed legislation to initiate a “foolproof” death penalty, Columbia Law School Professor Jeffrey Fagan (pictured) analyzed recent studies that claimed that capital punishment deters murders. He stated that the studies “fall apart under close scrutiny.” Fagan noted that the studies are fraught with technical and conceptual errors, including inappropriate methods of statistical analysis, failures to consider all relevant factors that drive murder rates, missing data on key variables in key states, weak to non-existent tests of concurrent effects of incarceration, and other deficiencies.
“A close reading of the new deterrence studies shows quite clearly that they fail to touch this scientific bar, let alone cross it,” Fagan said as he told members of the committee that the recent deterrence studies fell well short of the demanding standards of social science research. (J. Fagan, Public Policy Choices on Deterrence and the Death Penalty: A Critical Review of New Evidence, testimony before the Joint Committee on the Judiciary of the Massachusetts Legislature on House Bill 3934, July 14, 2005). Read the full text of Fagan’s testimony.
- Death Penalty Information Center (2025, March 14). Expert Testimony Faults Death Penalty Deterrence Findings. Retrieved October 2, 2026, from https://deathpenaltyinfo.org/expert-testimony-faults-death-penalty-deterrence-findings
- Death Penalty Information Center. “Expert Testimony Faults Death Penalty Deterrence Findings.” Last modified March 14, 2025. Accessed October 2, 2026. https://deathpenaltyinfo.org/expert-testimony-faults-death-penalty-deterrence-findings.
- Death Penalty Information Center. “Expert Testimony Faults Death Penalty Deterrence Findings.” Death Penalty Information Center, 14 Mar. 2025, https://deathpenaltyinfo.org/expert-testimony-faults-death-penalty-deterrence-findings. Accessed 2 Oct. 2026.
