The American Death Penalty Decline

American death sentences have both declined and become concentrated in a small group of counties. In his dissenting opinion in Glossip v. Gross in 2014, Justice Stephen Breyer highlighted how from 2004 to 2006, “just 29 counties (fewer than 1% of counties in the country) accounted for approximately half of all death sentences imposed nationwide.” That decline has become more dramatic. In 2015, fifty-one defendants were sentenced to death in thirty-eight counties. In 2016, thirty-one defendants were sentenced to death in twenty-eight counties. In the mid-1990s, by way of contrast, over 300 people were sentenced to death in as many as two hundred counties per year. While scholars and journalists have increasingly commented on this decline and speculated as to what might be causing it, researchers have not examined it empirically. This Article reports the results of statistical analysis of data hand-collected on all death sentencing, by county, for the entire modern era of capital punishment, from 1990 to 2016. This analysis of death sentencing data seeks to answer the question why a few counties, but not the bulk of the others, still impose death sentences. We examine state and county-level changes in murder rates, population, victim race, demography, and other characteristics that might explain shifting death sentencing patterns. We find that death sentences are strongly associated with urban, densely populous counties. Second, we find that death sentences are strongly associated with counties that have large black populations. Third, we find homicide rates are related to death sentencing in three ways: within and between death sentencing counties; within and between death sentencing counties following a lag to account for the time it can take for a case to proceed to a sentencing; and that counties with more white victims of homicide have more death sentencing. Fourth, we find that death sentencing is associated with inertia or the number of prior death sentences within a county. These results suggest what remains of the American death penalty is fragile and reflects a legacy of racial bias and idiosyncratic local preferences. We conclude by discussing the practical and legal implications of these trends for the much-diminished death penalty and for criminal justice more broadly