Unless the U.S. Supreme Court intervenes, a Utah firing squad will execute condemned murder Ronnie Lee Gardner shortly after midnight tonight. (Utah outlawed firing squads in 2004, but the state allows an exemption for death-row inmates who beforehand expressed a partiality for the method.)

Before you decide whether or not this is right, consider what Gardner did.

During a court appearance for the murder of Melvyn Otterstrom in 1985, Gardner tried to escape. He failed to do so, but in the process obtained a gun, injured court bailiff George Kirk and killed defense attorney Michael Burdell. According to press reports, Gardner makes no claims of innocence.

Some crimes are so heinous and inherently wrongful that legislatures have the moral responsibility to establish sentencing floors that include life sentences and the death penalty. The majority of Americans recognize this principle as just.

Foes of capital punishment have been very vocal in their opposition. But Gallup opinion polls consistently show that the American public overwhelmingly supports capital punishment. In Gallup's most recent poll, 65 percent of Americans favor the death penalty for those convicted of murder, while only 31 percent are opposed. Americans have consistently supported capital punishment by a 2-1 ratio in favor.

Americans are wise to do so.

Several studies have shown a link between death penalty executions and decreases in murder rates. In fact, studies done in recent years, using sophisticated statistical methods, consistently demonstrate a strong link between executions and reduced murder incidents.

• In a study of more than 3,000 counties from 1977 to 1996, professors Hashem Dezhbakhsh, Paul R. Rubin and Joanna M. Shepherd of Emory University found that each execution, on average, results in 18 fewer murders per county. Another study using data from 1960 to 2000 by Dezhbakhsh and Shepherd found that executions had a highly significant negative relationship with murder incidents -- i.e., the higher the number of executions, the lower the number of murders.
• Separately, Shepherd's analysis of monthly data from 1977 to 1999 found three important things. First, each execution, on average, is associated with three fewer murders, including both crimes of passion and murders by intimates. Second, executions deter the murder of all races. Third, shorter waits on death row are associated with increased deterrence. For each additional 2.75-year reduction in the death-row wait until execution, one murder is deterred.
• Two studies by Paul R. Zimmerman, a Federal Communications Commission economist, found that each additional execution, on average, results in 14 fewer murders, based on state-level data from 1978 to 1997, and that executions by electrocution are the most effective at providing deterrence.
• A more recent study by Kenneth C. Land of Duke University and his co-authors found that each additional execution in Texas from 1994 to 2005 was associated with a decrease of up to 2.5 murders.

In short, capital punishment does, in fact, save lives.

Yet, despite strong public support for capital punishment and its clear deterrent effect, federal, state and local officials must continually ensure that its implementation rigorously upholds constitutional protections, such as due process and equal protection of the law. However, the criminal process should not be abused to prevent the lawful imposition of the death penalty in appropriate capital cases.

Moral indignation is an appropriate response to inherently wrongful conduct carried out intentionally by Ronnie Lee Gardner. While the goal of lower crime through deterrence is worthwhile, lawmakers need to place special emphasis on the moral gravity of offenses in determining the proportionality of punishment.

The impending execution of Ronnie Lee Gardner is morally just, and may save the lives of others.

David B. Muhlhausen is a senior policy analyst in the Center for Data Analysis at the Heritage Foundation.