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PolitiFact VA: Does the Death Penalty Deter Murder?

Woman speaking
Sen. Barbara Favola (D-Arlington) answers a question during the Virginia Senate session at the Science Museum in Richmond, Va., Tuesday, Feb. 16, 2021. (Photo: Steve Helber/AP)

Speaker: Barbara Favola
Statement: “States that have abolished the death penalty have murder rates that are lower.”
Date: Feb. 3
Setting: Floor speech

The state Senate recently voted to repeal Virginia’s death penalty after a poignant debate that often focused on an age-old question: Does capital punishment deter murder?

Sen. Barbara Favola, D-Arlington, said it does not. “In fact, the states that have abolished the death penalty have murder rates that are lower, consistently lower,” she said in a Feb. 3 floor speech.

We looked into Favola’s statement, and found a mixed bag. Data since 1990 consistently show states that bar executions, when considered as a whole, do have lower murder rates than those that allow capital punishment. But many economists who have studied these numbers say they are statistically meaningless.

We decided to lay out the issues surrounding Favola’s statement, but not rate it on the Truth-O-Meter.

The numbers:
Favola in her speech attributed the data to the American Civil Liberties Union. The organization lists on its website many reasons to stop executions, including the claim that it does not deter murder. One proof the ACLU offers is that “between 1990 and 1994, the homicide rates in Wisconsin and Iowa (non-death penalty states) were half the rates of their neighbor, Illinois – which restored the death penalty in 1973, and by 1994 had sentenced 233 persons to death and carried out two executions.”

The ACLU also says that “between 2000-2010, the murder rate in states with capital punishment was 25-46% higher than states without the death penalty,” and hyperlinks to charts posted by the Death Penalty Information Center, a nonprofit that provides data and information on capital punishment.

The Center’s statistics come very close to matching the ACLU’s statement; the murder rates that decade were 23-47% higher in capital punishment states. Another chart shows the murder rate, as a whole, was higher in death penalty states every year from 1990 to 2018 - the latest year listed. That year, there were 5.3 homicides per 100,000 people in execution states compared to 4.1 per 100,000 in non-execution states.

Twenty-seven states had laws allowing the death penalty in 2018, 20 did not, and three states had gubernatorial-imposed moratoriums. Currently, 25 states allow capital punishment, 22 do not, and three have moratoriums.

The issues:
A number of economists say the comparison of murder rates between execution and non-execution states provides insufficient data to prove whether capital punishment deters murders.

Since the Supreme Court’s 1976 decision to reinstate capital punishment, 1,532 people have been put to death in the U.S. Although many say that’s a staggering number, it’s not a large sample size for economic study. The sample becomes much smaller when individual states are compared or when numbers are broken down by years.

The death penalty “is applied so rarely that the number of homicides it can plausibly  have caused or deterred cannot reliably be disentangled from the large year-to-year changes in the homicide rate caused by other factors,” concluded a 2009 study by John Donohue III, a Stanford economist and law school professor, and Justin Wolfers, an economist now at the University of Michigan.

In other words, a person intent on murder might have little reason to fear the death penalty. For example, there were 23,440 murders in 1990 and 23 executions; 16,740 murders in 2005 and 60 executions; 16,374 murders in 2018 and 25 executions.

Many death sentences are overturned on legal appeals. According to the Bureau of Justice Statistics, 8,466 death sentences were handed down between 1973 and 2013 and 1,359 resulted in executions. Another 3,619 of the sentences were overturned on appeal and many others were still in the process of appeals. The Bureau stopped keeping this data set after 2013.

Another problem in studying the deterrence effect is the length of time it takes between a person’s capital murder conviction and his execution - an average 12 years in 2000, and 20 years in 2018. “The theory of deterrence is predicated on the idea that if state-imposed sanction costs are sufficiently severe, certain, and swift, criminal activity will be discouraged,” the National Academies of Science, Engineering and Medicine wrote in a 2012 study titled “Deterrence and the Death Penalty.”

The study concluded there is no “evidence for or against the proposition that the death penalty affects homicide rates.” 

Also hampering researchers is that the definition of capital murder varies in death penalty states. Some apply it to a relatively broad group of homicides, others restrict it to very limited circumstances, and the laws have changed over time. Donahue and Wolfers wrote that it is unlikely many potential murderers know “the precise details of capital punishment” in their states well enough to conclude they would face great risk of execution.

Bottom line: There are riveting arguments against and for the death penalty based on morality and justice. But the footing softens when debaters declare it does, or does not, deter murder in the U.S.

Sources:
Sen. Barbara Favola, floor speech, Feb.3 2021 (1:11:30 mark).
Legislative Information System, SB 1165, 2021 session.
ACLU, “The Case Against the Death Penalty,” accessed Feb. 8, 2021.
Death Penalty Information Center, “Murder Rates of Death Penalty States Compared to Non-Death Penalty States,” accessed Feb. 12, 2021.
DPIC, “Executions by State and Region Since 1976,” accessed Feb. 16, 2021.
John Donohue and Justin Wolfers, “Estimating the Impact of the Death Penalty on Murder,” December 2009.
The Disaster Center, “United States Crime Rates 1960 - 2019.”
Bureau of Justice Statistics, “Capital Punishment 2018 - Statistical Tables,” published September 2020. 
BJS, “Capital Punishment, 2013 – Statistical Tables,” revised Dec. 19, 2014.
National Academies of Science, Engineering and Medicine, “Deterrence and the Death Penalty,” 2012