Capital jury decision-making: The limitations of predictions of future violence.

Abstract

The U.S. Supreme Court in Jurek v. Texas (1976) affirmed that capital juries are able to identify those capital offenders who will commit serious violence in the future. The capability of capital juries to accurately make these judgments as a means of deciding which capital offenders should receive the death penalty has been widely endorsed in both statute and case law, as well as embraced by jurors. A growing body of research on rates and correlates of prison violence, however, points to this confidence being misplaced. Prior investigations of the accuracy of these capital jury predictions, though limited in number, have found alarming error rates. The current study retrospectively reviewed the post-trial (M ϭ 5.7 years) prison disciplinary misconduct of federal capital offenders (N ϭ 72) for whom juries considered "future dangerousness" as an aggravating factor at sentencing. These jurors' predictive performance was no better than random guesses, with high error (false positive) rates, regardless of the severity of the anticipated violence. In light of prior studies, it is concluded that juror predictions of future violence lack sufficient reliability to play a role in death penalty determinations.

Inmate homicides: Killers, victims, motives, and circumstances

“…A handful of prior studies have reported on rates of prison homicide among inmates who had been sentenced for murder (Sorensen & Pilgrim, 2000;Wolfson, 1982) or capital murder , 2008Cunningham & Sorensen, 2007aCunningham, Sorensen, & Reidy, 2009;Marquart, Ekland-Olson, & Sorensen, 1989, 1994Reidy, Cunningham, & Sorensen, 2001;Sorensen & Wrinkle, 1996). In some of these studies, there were no prison homicides among the convicted murderers.…”

Black vs. White, Life vs. Death; Using Automatic vs. Controlled Processing as a Framework for Understanding Racial Disparities in the Criminal Justice System

“…Because the incidence of violence in heavily guarded prisons where there is little opportunity for inmate interaction to occur is very low, predicting these rare events is difficult. One analysis showed that prison homicides in capital offenders ranged from 0.002 (that is 1/5 of 1%) to 0.01 (1%), so jurors and clinicians are likely to hugely overestimate the likelihood of capital offenders committing another homicide [38].…”

“…In 155 affirmative "special issue" cases where juries were presented with expert mental health testimony that the person would be violent, violence rates among executed inmates, those pending execution, and execution relieved populations were equivalent. Violence estimates among those affirmative cases ranged from between 4 and 7%, so the predictions were wrong 93% to 96% of the time [38]. Because there is so little violence in prison, predictions about these rare occurrences are likely to include many false positives.…”

“…Because to that question, the answer must always be "yes". Perhaps instead of probability, the question should be phrased as "more likely than not" or "disproportionately more likely than other inmates" to pose a threat [38,40]. In addition, when jurors interpret "society" they most likely think of their community rather than the highly guarded "society" of a prison.…”

Risk Assessment in the Law: Legal Admissibility, Scientific Validity, and Some Disparities between Research and Practice

“… Other scholarly critiques of risk assessment expert testimony include: (1) whether the accuracy of risk assessments can ever reach the requisite legal standard for adjudications that may involve life or death or lifetime confinement (e.g., Cunningham, Sorensen, & Reidy, ); and (2) whether more structured approaches to risk assessment are fundamentally flawed (e.g., Wollert, ). Both these additional questions are beyond the scope of this article.…”