When Marion Bowman was arrested at age 20 for the murder of Kandee Martin, society did not consider him mature enough to drink alcohol, rent a car, or enter a casino. Yet he was deemed old enough to be sentenced to death. Now 44, he has spent over half his life on South Carolina’s death row and is scheduled for execution on January 31. “Retribution is not proportional if the law’s most severe penalty is imposed on one whose culpability or blameworthiness is diminished, to a substantial degree, by reason of youth and immaturity,” the United States Supreme Court reasoned when it prohibited the death penalty for criminal defendants under the age of 18 in Roper v. Simmons (2005). A growing body of neuropsychological research has found that the same deficits in critical thinking, impulse control, and susceptibility to peer pressure that motivated the Roper Court to exempt juveniles from execution also apply to “emerging adults” aged 18 – 20. And evidence suggests that the death penalty is disproportionately applied to youthful Black offenders like Mr. Bowman, who if his execution proceeds will become the fifth Black prisoner in South Carolina put to death in the modern era for a crime committed under age 21 — compared to just one white prisoner.