Deterrence and the Death Penalty

DPI’s ​“What to Know” series exam­ines cap­i­tal pun­ish­ment from mul­ti­ple angles, one top­ic at a time. 

Each install­ment pro­vides essen­tial facts and data on spe­cif­ic aspects of the death penalty.

Why it mat­ters: Deterrence is among the most com­mon­ly cit­ed jus­ti­fi­ca­tions for the death penal­ty, yet decades of research have failed to pro­duce cred­i­ble evi­dence that use of the death penal­ty has an impact on homicide rates.

Key Facts:

• 88% of the nation’s lead­ing crim­i­nol­o­gists said they did not believe the death penal­ty deters homi­cides. Just 9% agreed that ​“the death penal­ty sig­nif­i­cant­ly reduces the num­ber of homicides.”
• When states have abol­ished the death penal­ty, mur­der rates have not fol­lowed any con­sis­tent pat­tern of change. Rates in states that for­mer­ly retained the death penal­ty fol­low nation­al trends rather than spik­ing or falling after abolition.

Studies Consistently Debunk Assertions that the Death Penalty Deters Homicide

In 2012, the National Research Council (NRC) released a com­pre­hen­sive review, Deterrence and the Death Penalty, of more than three decades of post-Gregg v. Georgia (1976) research that con­clud­ed exist­ing stud­ies on deter­rence ​“are not infor­ma­tive about whether cap­i­tal pun­ish­ment decreas­es, increas­es, or has no effect on homi­cide rates,” and explic­it­ly rec­om­mends that they ​“not be used to inform delib­er­a­tions” about the death penal­ty. The NRC iden­ti­fied three com­pound­ing flaws in exist­ing deter­rence research: stud­ies fail to account for the effects of non-cap­i­tal pun­ish­ments; they rely on implau­si­ble mod­els of how poten­tial mur­der­ers per­ceive and respond to exe­cu­tion risk; and they are built on sta­tis­ti­cal assump­tions that are not cred­i­ble and can­not be confirmed.

“…[C]laims that research demon­strates that cap­i­tal pun­ish­ment decreas­es or increas­es the homi­cide rate by a spec­i­fied amount or has not effect on the homi­cide rate should not influ­ence pol­i­cy judg­ments about capital punishment.” — National Research Council, Deterrence and the Death Penalty

Unlike like its 1978 pre­de­ces­sor report, the NRC’s 2012 report offered three con­crete rec­om­men­da­tions for future research: col­lect stronger data on cap­i­tal and non-cap­i­tal com­po­nents of the pun­ish­ment scheme for homi­cides; study how poten­tial mur­der­ers actu­al­ly per­ceive and respond to the risk of sanc­tion, rather than assum­ing response to objec­tive sta­tis­tics; and use sta­tis­ti­cal meth­ods that rely on ​“less strong and more credible assumptions.”

“The sci­en­tif­ic com­mu­ni­ty has found no reli­able evi­dence of the death penal­ty being a deter­rent to homicides…Murder rates are and have been inde­pen­dent of the impo­si­tion of the death penal­ty of the insti­tu­tion of hav­ing a death penalty.” — Wyandotte County District Judge Bill Klapper, in an April 2025, order in the com­bined cas­es of Hugo Villanueva-Morales and Antoine Fielder.

Other Countries Experience Lower Murder Rates Than the U.S. — Without the Death Penalty

• In the European Union, where all mem­ber coun­tries have abol­ished the death penal­ty, every coun­try has a low­er mur­der rate than the United States.
• More broad­ly, as of 2018, of the eleven coun­tries that had abol­ished the death penal­ty between 2008 and 2018, ten expe­ri­enced a decline in mur­der rates post-abolition.

Source: Death Penalty Information Center, Staff, March 4, 2026

"One is absolutely sickened, not by the crimes that the wicked have committed,
but by the punishments that the good have inflicted."

— Oscar Wilde

Death Penalty News For a World without the Death Penalty