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.
TABLE OF CONTENTS INTRODUCTION 563 I. THE EMPIRICAL STUDY OF DEATH SENTENCING 568 A. Prior Research on Death Sentencing in the U.S 568 B. Data Sources 575 1. Death Sentencing Data 575 2. Homicide Data 577 3. Race 579 4. Population Density 580 5. Income 580 C. Empirical Strategy 581 II. FINDINGS: EXPLAINING THE DECLINE IN DEATH SENTENCING 583 A. Descriptive Trends 583 B. Baseline Analyses 592 C. Analysis of Disaggregated Homicide Rates 595 D. Analysis of Lagged Homicide Rates 597 E. Path Dependency in Death Sentencing 599 F. Robust Results 602 III. PRACTICAL AND CONSTITUTIONAL IMPLICATIONS OF STUDY FINDINGS 604 A. Population Density Findings 605 B. Race of Victim and Demographic Findings 606 C. Homicide Rate Findings 606 D. Eighth Amendment Implications 607 E. Implications for Future Death Penalty Trends 613 F. Implications for Criminal Justice 614 CONCLUSION 615 APPENDIX 616 INTRODUCTION
In the span of fifteen years, American death sentences have become rare and concentrated in a vanishingly small group of counties. In his dissenting opinion in Glossip v. Gross in 2014, Justice Stephen Breyer suggested that the death penalty may now be categorically unconstitutional, noting "dramatic declines" in death sentences even in states like Texas and Virginia. (1) Even within such states, Justice Breyer noted that "[g]eography also plays an important role in determining who is sentenced to death" and that "[b]etween 2004 and 2009, for example, just twenty-nine counties (fewer than 1% of counties in the country) accounted for approximately half of all death sentences imposed nationwide." (2) This Article describes how the decline has become still more dramatic since 2009, based on comprehensive data hand-collected on all death sentencing, by county, for the entire modern era of capital punishment. While scholars and journalists have increasingly commented on this decline and speculated as to what might be causing it, (3) empirical research has not comprehensively examined the question. (4) In this Article, we report results of detailed statistical analysis of these data to answer the question why a few counties, but not the vast bulk of the others, still impose death sentences. Is it murder rates, or population, or demography, or some other characteristic of these counties that explain their death sentencing? We examine characteristics statistically associated with county-level death sentencing, and we conclude by raising important practical and constitutional questions for litigators and judges.
The American criminal justice system is imposing fewer death sentences than at any point in the past three decades. Just fifty-one defendants were sentenced to death in 2015. (5) In 2016, just thirty-one defendants were sentenced to death. (6) In the 1990s, several hundred people were sentenced to death each year. (7) The rapid and stunning drop in death sentences is even more marked at the local level. There are over 3,000 counties in the U.S. (8) Very few counties have imposed death sentences, even in states with the death penalty. Through the 1990s, death-sentencing counties were more widely dispersed, and small rural counties regularly imposed death sentences. (9) Even within the biggest death penalty states, death sentences now come from a shrinking group of individual counties, like Riverside County, California and Duval County, Florida. (10) While the local patterns documented in this paper may be less visible to the public, the forces driving away the death penalty are working fastest at the county level. Today, few counties still sentence individuals to death. The smaller counties simply do not seek the death penalty any longer.
In Part I, we review the literature and describe prominent studies assessing death sentencing patterns. In the 1980s, scholars began to conduct systematic research collecting data on the use of the death penalty at the county level, beginning in individual states with the pioneering work of David Baldus, and ultimately studying groups of states and patterns across all death penalty states. (11) The Baldus study found that death-sentencing rates were highest in rural areas of Georgia but that death-sentencing patterns were quite uniform across the state. (12) The first study to report national death sentencing data comprehensively was the landmark "Broken System" study led by Professors James Liebman, Valerie West, and Jeffrey Fagan, which examined death sentences from 1973 through the early 1990s. (13) Follow-up research found a concentration of death sentences in a small minority of counties. (14) The authors noted: "Even in Texas, nearly 60% of its counties did not impose a single death sentence in the period." (15) That research has been updated, in part. A study by Professor Robert J. Smith of death sentences between 2004 and 2009 found: "The geographic distribution of death sentences reveals a clustering around a narrow band of counties: roughly 1% of counties in the United States returned death sentences at a rate of one or more sentences per year from 2004 to 2009." (16) Today, as we will describe, even leading death-sentencing counties have experienced dramatic declines in death sentences.
The decline in executions is still more pronounced than the decline in death sentences. Of the over 8,000 death sentences handed down from 1977 through 2015, just over 1,400 persons have been executed. (17) A Death Penalty Information Center report analyzing executions since 1976, including data collected by Professor Frank Baumgartner, found that 2% of counties in the U.S. were responsible for a majority of the executions, and 85% of the counties in the U.S. had not had an execution in over 45 years. (18)
In the second and third sections of Part I, we explain our research design and how we analyze hand-collected data on death sentencing in the United States for the time period from 1991-2016. (19) We first explain how that data on death sentencing was collected. We then explain how we obtained and how we analyzed homicide data, data on race and racial fragmentation in counties, population density data, and income data. Finally, we explain the empirical strategy, including the statistical models employed to analyze death-sentencing data.
In Part II, we present the results. In this Article, we analyze county-level death sentencing during the modern era to try to answer why some counties sentence individuals to death where others do not. First, we describe a change in the composition of death sentencing counties from the 1990s, at the height of the modern era of death sentencing in the United States, through the past decade. Far fewer rural and less-populated counties continue to impose death sentences. Instead, population density is strongly associated with death sentencing. (20) However, those large counties have also experienced the sharpest declines in death sentencing.
Second, we find that counties with large black populations engage in more death sentencing. (22) Many studies have found that death sentences are disproportionately imposed in cases in which the victim is white. (23) We found that an increase in black homicide rates is not associated with an increase in county-level death sentencing, while cases with white homicide victims are. Those two factors, presence of large black population centers and white homicide victimization, have been associated with death sentencing in prior studies and with a troubling use of the death penalty to respond to a perceived, although not accurate, racialized sense of threat. (24)
Third, we find that homicide rates are connected with death sentencing in the basic...