ARTICLE: A Statistical Analysis of Predictors Associated with the Dramatic Decline in Death Sentences in the United States in the Last Two Decades

The annual number of new death sentences in the United States has fallen by more than 75% in the last two decades. The current study examines 1,665 death-eligible cases from 1994, 2004, and 2014 to draw empirically based conclusions that can shed light on some significant predictors associated with this dramatic decline. The results of logistic regression models suggest that the following were consistently significant predictors of case outcomes throughout the country over time: multiple perpetrators, age of perpetrators between 18 and 20 years, number of mitigators, cases with high and low aggravation, and five formerly high-volume counties. By contrast, factors that were important predictors of case outcomes in 1994 but that became insignificant in later years were robbery-murder and limited-revenue counties; the murder rate was not significant in 1994 but became significant in later years. Allegations of intellectual disability and county population size were not significant predictors in any of the years. _______________________________________________________________________________ The number of new death sentences in the United States fell from 310 in 1994 to 73 in 2014. The media have noticed this sharp decline of more than 75% (Khadaroo, 2014; Wolf & Johnson, A Statistical Analysis of Predictors Associated with the Dramatic Decline in Death Sentences in the United States in the Last Two Decades Journal of Criminal Justice and Law: Official Journal of the Law and Public Policy Section of the Academy of Criminal Justice Sciences Volume 3, Issue 1, pp. 1-21 (2019) 2 Talia Roitberg Harmon and David McCord 2015). In this article, we examine a host of death-eligible cases to draw empirically based conclusions that illuminate some of the significant predictors of case outcome over time. We chose 10 possible predictors for hypothesis testing: level of case aggravation, robbery as an aggravator, size of county population, county financial resources, changes in five populous counties, multiple perpetrators, number of kinds of mitigation evidence presented, claims of intellectual disability, perpetrator age between 18 and 20 years, and murder rate. We tested these predictors for 3 years: 1994, 2004, and 2014. We selected these years for two reasons. First, when we began the project, 2014 was the most recent year for which data were available. Second, this choice allowed us to backtrack two decades to 1994, which was one of the peak years for death sentence imposition in the post-Furman, contemporary death penalty era. The year 2004 then became a midpoint year to examine what was happening between 1994 and 2014. We employed a comparison methodology for death-eligible cases, which was necessary “to ensure that what is being observed is not merely a correlate” (Gould, Carrano, Leo, & Hail-Jares, 2014, p. 479). Specifically, we split the cases into two groups: those in which the defendants were sentenced to death, and those in which defendants were spared the death sentence by prosecutor or sentencer (usually a jury but occasionally a judge) decisions. Analysis of the factors that predicted case outcome generated important insights into the continued, but declining, operation of capital punishment in the United States. This is the first scholarly paper to statistically examine possible correlates of the decline in death sentences over two decades from a nationwide perspective on the basis of the details of more than 1,600 individual cases, thus providing an exceedingly fine-grained analysis.