In Arkansas, is this capital punishment's last gasp?

The nation and the world took notice as Gov. Asa Hutchinson of Arkansas began an effort to execute eight prisoners in the course of less than two weeks, just before the state's supply of a drug used in executions expires. On April 20, the first of these men, Ledell Lee, was given a lethal injection using the soon-to-expire drug. It has been a riveting back-and-forth as multiple courts have stepped in to delay the executions.

While it is tempting to see the drama in Arkansas as symbolic of a revival of the death penalty, it more likely represents the opposite — a shudder as capital punishment fades away. Last year there were only 20 executions in the U.S., down from 98 in 1999, and the lowest total in 25 years. Here in Minnesota, we took the death penalty off the table more than a century ago. The decrease in executions elsewhere, though, has not been the result of changes in the law — 31 states still retain the death penalty — but rather because it is being used much less often in those states where it is allowed. It's striking that last year there were more states with capital punishment on the books than there were actual executions.

Experts point to many causes for the decline, including the expansion of life without parole sentences as an alternative to capital punishment, legal challenges to implementation of death sentences, and a shortage of the drugs used to kill prisoners. In some places, the high cost of capital trials and appeals (where the government almost always funds both the prosecution and the defense) deters prosecutors from seeking the death penalty. In other instances, prosecutors may be less likely to seek the death penalty because they see the writing on the wall — that jurors are less likely to give them that win.

A majority of Americans still supports the death penalty in the abstract, yet it is American citizens who have been undoing it when confronted with an individual defendant. While it is difficult to fully see the complex web that makes up the thinking of citizens in their roles as jurors and prosecutors, it does seem that the undoing of two myths has played a role in the changing attitudes of those who make these crucial decisions. First, the innocence and exoneration of many people sentenced to death have challenged the myth of certainty — that we are always right when we ascertain that someone is guilty and deserves to die. Second, there has been a successful public challenge to the myth of deterrence — that the presence of the death penalty convinces people not to commit murders.

The myth of certainty has suffered a hard fall. Since 1973, more than 155 people on death row have been exonerated based on evidence of their actual innocence of the crime. Most often, that evidence has come in the form of DNA and the increased ability of science to match tiny samples to one individual. Overall, the National Registry of Exonerations includes more than 2,000 people wrongly convicted of crimes, both capital and noncapital. While our system may be good, it is far from perfect. When the consequence of a mistake by a capital jury is the killing of an innocent — the very crime that the death penalty supposedly addresses — it undermines the project as a whole. As exonerations have mounted, faith in the death penalty has understandably declined. For those poor souls paid $40 a day to decide whether someone lives or dies, the cost of possibly being wrong is sometimes just too high.

The myth of deterrence continues to resonate in many quarters, despite persistent criticism. The overwhelming majority of criminologists don't believe that capital punishment deters crime. Because it involves things hidden in human minds, deterrence is a difficult thing to measure, though; in 2012, the National Research Council of the National Academies issued a report concluding that studies of deterrence were fundamentally flawed, and should not influence policy decisions one way or the other. Common sense tells us that deterrence probably is not a factor in the types of killings most often leading to the death penalty. For deterrence to work, those who consider murder must make a rational cost-benefit analysis that factors in potential penalties. In the midst of a robbery, that kind of analysis does not take place.

The events in Arkansas are aberrational, but important, and even as capital punishment fades in America the world pays attention to our actions. The Arkansas governor's rush to execute is troubling, even after the extended period these inmates spent on death row. Justice and haste rarely travel together.

Mark Osler is the Robert and Marion Short Professor of Law at the University of St. Thomas and author of "Prosecuting Jesus."