A new study suggests that Idaho’s capital punishment statute fails to narrow the use of the death penalty to the “worst of the worst” crimes, raising questions about its constitutionality. In Narrowing Death Eligibility in Idaho: An Empirical and Constitutional Analysis, published in the February 2022 issue of the Idaho Law Review, Aliza Plener Cover (pictured) argues based on data from nearly 20 years of murder convictions that the Idaho legislature “has done little to meaningfully narrow a subset of those who are most deserving of death.”

Cover, an Associate Dean of Faculty & Professor of Law at the University of Idaho College of Law, reviewed first- and second-degree murder convictions in Idaho in cases filed between June 2002 and December 2019. Noting that U.S. Supreme Court case precedent requires that a “statutory scheme governing the imposition of the death penalty must meaningfully differentiate between those ‘worst’ murderers, who may be subject to the death penalty, and the rest of murderers, who may not,” Cover writes that Idaho has failed to meaningfully limit eligibility for the death penalty.

Cover’s review of the facts underlying the crimes for which defendants were convicted of murder in Idaho found that the vast majority of cases qualified as death-eligible under the state’s death penalty law. Factually, 86-90% of all murder convictions qualified as first-degree murder cases, she said, and the facts in 93-98% of those cases made them eligible for the death penalty. Whether a case proceeded as capital, however, depended largely on the whims of individual prosecutors. Of those factually death-eligible cases, she found, prosecutors filed a notice of intent to seek the death penalty in only 21% and proceeded to a capital trial in 5% of death-eligible cases. Ultimately, death sentences were imposed in only 3% of death-eligible cases.

“The dramatic disparity between the high death eligibility rate and the low death charging and sentencing rates suggests that the primary reason for the small number of death sentences in Idaho is not legislative guidance about capital eligibility, but rather prosecutorial discretion,” Cover says.

“Nearly fifty years after Furman was decided, the death penalty’s use in Idaho is being constrained not by reasoned and even-handed legislative judgment, but by prosecutorial discretion,” Cover concludes. “The data gathered in this study — showing a high rate of statutory death eligibility and a low rate of death charging and sentencing — is strong evidence that Idaho’s capital punishment scheme, on an aggregate level, does not meet the Eighth Amendment narrowing requirement.”

The constitutional requirement that the death penalty be reserved for the “worst of the worst” requires narrowing at two distinct steps. First, the legislature is required to adopt statutory criteria that differentiate between the “worst” murders and murderers s who may be subjected to the death penalty, as compared to other non-capital murders and murderers. Second, factfinders at trial can consider mitigating evidence to determine whether an individual defendant should be sentenced to death. Cover’s study focused on the former.

“The Supreme Court has specifically required legislative narrowing of capital eligibility – rather than relying on discretionary prosecutorial selection of which death-eligible cases to pursue capitally,” she explains. “Legislatures may not constitutionally abdicate their narrowing responsibility to prosecutors.”

“These findings strongly suggest that Idaho’s statute fails to fulfill the constitutional narrowing requirement,” Cover argues. “The overwhelming majority of murderers in Idaho are eligible for the death penalty; the legislature has done little to meaningfully narrow a subset of those who are most deserving of death.”