Improbable predictions at capital sentencing: contrasting prison violence outcomes.

The postconviction prison disciplinary records of capital defendants (n = 73) who had been the subject of defense-sponsored violence risk assessments or risk-related testimony (1995-2007) that asserted an improbability of future serious prison violence were analyzed. During postconviction prison tenures averaging 4.4 years, none of the capital defendants was cited for accomplished serious assaults. The prevalence of misconduct was inversely related to severity: 54.8 percent were cited for some disciplinary misconduct, 27.4 percent for potentially violent disciplinary violations, 12.3 percent for assaultive misconduct, and 1.4 percent for attempted serious assault. Rates of misconduct among the capital offenders were equivalent to those among all inmates (n = 18,561, annual average) in high-security federal prisons (2001-2005). The accuracy rate of forecasts of improbability stands in sharp contrast to that of prosecution-sponsored expert testimony at capital sentencing that had asserted high rates of future violence.