Does the Death Penalty Deter Crime?

Many people sentenced to death are never executed. In 2023, five states carried out 24 executions, according to the Bureau of Justice Statistics (BJS), while 64 people left death row another way, 34 because a court overturned the conviction or the death sentence and 30 because they died of other causes.

Whether the death penalty deters murder, and what it costs, both come down to what it adds over the punishment the same murderer would otherwise get. In all 27 states that the Death Penalty Information Center (DPIC) counts as having the death penalty, the alternative sentence can be life without parole. The most common capital offense is first-degree murder with at least one aggravating factor that the law lists, such as a murder committed during a kidnapping or an armed robbery.

Source: Bureau of Justice Statistics, Capital Punishment, 2023 – Statistical Tables (2025). Four states with a statute (Delaware, New York, Oregon and Wyoming) held no one under sentence of death, and New Hampshire, which repealed its statute in 2019, still held one man sentenced before the repeal. DPIC counts 27 states with the death penalty, because it lists Delaware and New York, whose top courts struck down part of their death penalty statutes, among the states without it.

In 1975 the economist Isaac Ehrlich, using national figures for 1933 to 1969, estimated that each additional execution a year may have meant 7 or 8 fewer murders on average. In 1978 a National Research Council panel found his results sensitive to minor changes in the model and unstable over time, and concluded that the studies then available gave “no useful evidence” on whether the death penalty deters.

In 2003 Hashem Dezhbakhsh, Paul Rubin and Joanna Shepherd, using data for 3,054 U.S. counties from 1977 to 1996, reported that each execution meant 18 fewer murders on average, give or take 10. In 2005 Richard Berk, a UCLA statistician, found that several such claims rested on the few state-years with more than five executions, about 1% of the data.

Shepherd later split the same data by state. Of the 27 states that carried out executions in those years, she found that executions deterred murder in 6, made no difference in 8 and increased murders in 13, which she called brutalization. Where executions did not deter, she wrote, they “kill convicts uselessly” if deterrence is their purpose.

In 2005 the law professor John Donohue and the economist Justin Wolfers re-ran the recent studies claiming deterrence. The county study relied on four state figures to tell cause from effect: police payrolls, court spending, prison admissions and the Republican share of the presidential vote. Using its authors’ own data and code, they found that entering the vote share as one figure, as the paper describes, instead of the six its code used, turned 18 lives saved per execution into 18 lost. Across the study’s six versions of its model, using only the vote shares gave as many as 429 lives saved, and using only the other three figures as many as 86 lost. Once the margin of error around the published 18 allowed for counties in the same state moving together, it ran from each execution causing 82 more murders to each saving 119 lives. Executions are so rare, they concluded, that their effect on murder cannot be reliably told apart from the large swings in murder from year to year.

In 2012 a National Research Council committee chaired by Daniel Nagin concluded that “research to date on the effect of capital punishment on homicide is not informative about whether capital punishment decreases, increases, or has no effect on homicide rates.” It found that none of the studies accounted for the punishment a murderer would otherwise get, usually a long prison term or life without parole, and that all of them relied on unproven assumptions, including about how potential murderers judge their risk of execution. A lack of evidence, it stressed, is not evidence for or against deterrence.

In 2021 Brett Parker compared seven states that had recently abolished the death penalty with blends of the 29 that kept it, and found no evidence that a death penalty law deters murder, even the murder of strangers.

How to read it: each bar is how many lives one execution saved, net, in the version of the county study that gave its 18, as Donohue and Wolfers re-ran it with the authors’ data and code; below zero means more deaths. Source: Donohue and Wolfers (2005).

The National Institute of Justice, drawing on Daniel Nagin’s 2013 review of the research, says the chance of being caught deters far more than even draconian punishment. Executions themselves are rare. In 2024 there were 25, while the Centers for Disease Control and Prevention counted 20,162 homicide deaths; by DPIC’s count, executions nearly doubled in 2025.

Six state studies compared capital murder cases with similar cases where death was not sought, or with a system without the death penalty, and each found the capital cases cost more on average. They measure different things, and each row says what it compares.

The difference starts before the trial. Once prosecutors seek death, jurors are questioned about their views on it (Kansas’s auditors counted 230 screened on average, against 89 in other murder trials), each side usually has two lawyers, and a guilty verdict is followed by a second trial on the sentence, with its own witnesses and experts. In Maryland about 70% of the extra cost of seeking death fell at the trial stage. A death sentence then brings an automatic review by the state’s highest court, which most other sentences do not get, and years of further challenges that the prisoner can bring.

Seeking death costs more even when no death sentence follows. In Nevada such a case cost $1.2 million, against $775,000 where death was never sought, and in Maryland $1.8 million against $1.1 million. Kansas’s auditors concluded that because the U.S. Supreme Court requires so much of the process, there appeared to be little room to save money by changing it.

How to read it: each bar is how much more a murder case ending in a death sentence cost than a similar case where death was not sought, in millions of dollars (Nevada’s is for a sentence not carried out). The other studies measure other things. Sources: Urban Institute (2008); Nevada Legislative Auditor (2014).

At the end of 2023, 41% of the people under sentence of death were Black, the Bureau of Justice Statistics reports, against 13.5% of the U.S. population in the Census Bureau’s 2025 estimate. That gap alone does not show bias, since it could reflect differences in the crimes, the defendants’ records or where the cases were tried. The question is whether gaps remain once those are taken into account.

In 1990 the U.S. General Accounting Office (GAO) reviewed 28 studies of death sentencing since 1972. In 82% of them, the victim’s race influenced the likelihood of a capital charge or a death sentence, and those who killed white victims were more likely to be sentenced to death than those who killed Black victims. The finding held in studies of high, medium and low quality, and the evidence was stronger at early stages such as charging, where larger samples allowed more rigorous analysis. Legally relevant factors such as aggravating circumstances were influential but “did not explain fully” the disparities.

In Georgia, David Baldus and his colleagues studied more than 2,000 murder cases from the 1970s. One of their models, as the Supreme Court summarized it in McCleskey v. Kemp (1987), found that even after 39 nonracial variables were taken into account, defendants charged with killing white victims were 4.3 times as likely to receive a death sentence as those charged with killing Black victims. The Court assumed the study was statistically valid, but held that to win under the Equal Protection Clause McCleskey had to prove that the decisionmakers in his own case acted with discriminatory purpose, which the study could not show.

How to read it: each bar is how many times higher the odds of a death sentence were when a victim was white, after the study’s statistical controls; a bar at 1 would mean no difference. The table shows which cases each study compares. The Supreme Court put Georgia’s figure as “4.3 times as likely”; Phillips and Marceau, who later reworked Baldus’s data, describe it as odds. Sources: Baldus and colleagues, as reported in McCleskey v. Kemp (1987); Paternoster and Brame (2003); Unah and Boger (2001).

In North Carolina, Wesley Jennings and colleagues matched 1,113 capital trials from 1977 to 2009 on about 50 case characteristics, and the white-victim effect on the jury’s sentence was no longer significant. Their study began after prosecutors had chosen to seek death, though, and in the Maryland study the victim’s race mattered at that choice, not at the sentence.

The evidence on the defendant’s race is less clear. The GAO called it “equivocal”, and the Maryland study found no evidence that the defendant’s race mattered once case characteristics were controlled for. In Washington, though, the study the state’s Supreme Court relied on when it struck down the death penalty in 2018 found that, once other factors were taken into account, Black defendants whose cases reached a death penalty hearing were 3.5 to 4.6 times as likely as others to be sentenced to death, depending on the model.

Where a murder happens matters too. In 2013 the Death Penalty Information Center found that 2% of U.S. counties accounted for most of the cases that had led to executions since 1976. In the Maryland study, prosecutors in Baltimore County were more than 13 times as likely to seek death as those in neighboring Baltimore City, even after controlling for the facts of each case. Where the homicide occurs, the study concluded, “matters and matters a great deal.”

The Death Penalty Information Center counts 203 people exonerated from death row since 1973, in 30 states, the latest in July 2026. The National Registry of Exonerations, which counts all crimes, recorded 147 exonerations in 2024, 85 of them for homicide and four of people who had been sentenced to death. Official misconduct played a part in at least 104 of the 147, or 71%, and in 79% of the homicide cases.

Counts miss the innocent who are never cleared, and the chance of being cleared drops sharply once a death sentence is reduced to life. In 2014 Samuel Gross and colleagues modelled this and estimated that if everyone sentenced to death stayed under that sentence indefinitely, at least 4.1% would be exonerated. The authors call the estimate conservative.

An execution cannot be undone, and errors can take decades to surface. Derrick Jamison received six death warrants during 20 years of wrongful imprisonment in Ohio, one of them within 90 minutes of being carried out; a federal court found that prosecutors had withheld 35 pieces of evidence, the charges were dropped in 2005, and in March 2026 a judge declared him wrongfully imprisoned. Elwood Jones spent 27 years on Ohio’s death row before a judge found in 2022 that prosecutors had withheld evidence; the charges were dropped in 2025. Tommy Lee Walker, a Black man arrested at 19, was sentenced to death by an all-white Dallas jury and executed in 1956 at 21. In January 2026 Dallas County declared him innocent.

The safeguards meant to catch such errors are also why capital cases cost more. Nevada’s auditor traced the extra spending to procedural safeguards “to ensure the sentence is just and free from error”.

No one has shown that the death penalty deters crime. In 2012 the National Research Council concluded that research on its effect is “not informative about whether capital punishment decreases, increases, or has no effect on homicide rates”, and recommended that the studies not be used to inform policy. It stressed that this lack of evidence is not evidence for or against deterrence.

The studies that claimed large effects did not hold up when others re-ran them. The 2003 county study behind the estimate of 18 murders prevented per execution gave 18 lives lost when one of its figures was entered as the paper itself describes, and its co-author, splitting the same data by state, found deterrence in 6 of 27 states and more murders in 13. Executions are rare, 25 in 2024 against 20,162 homicide deaths, and Donohue and Wolfers concluded that their effect cannot be reliably told apart from the year-to-year swings in murder.

The other questions have firmer answers. All six state studies of cost found capital cases cost more on average. In 82% of the 28 studies the GAO reviewed in 1990, the victim’s race influenced the likelihood of a capital charge or a death sentence. And 203 people have been exonerated from death row since 1973.

Download the conclusion

The verdict above as one image, with its chart: the 2003 county study’s preferred model as Donohue and Wolfers re-ran it, 18.5 lives saved per execution as published, 17.7 lost with one vote-share figure as the paper describes, 52.3 lost with only the police, court and prison figures, 288.8 saved with only the vote shares. It is 1,200 by 630 pixels, the size social networks use for link previews; anyone may download and post it.

Download the card (PNG, 1,200 × 630)