In June 2003 Governor George Ryan of Illinois stirred controversy when he commuted the death sentences of 167 inmates to life imprisonment. Ryan said he had concluded the state's capital punishment system was "haunted by the demon of error." His action came three years after he ordered a moratorium on executions after evidence proved that 13 inmates on death row had been wrongly convicted. Ryan, a Republican, had sought office with a platform that supported capital punishment.

In a 1989 case, the U.S. Supreme Court upheld the execution of mentally retarded inmates. In the years following, however, many states enacted legislation to prohibit such executions. In 2002, in Atkins v. Virginia, the Supreme Court voted 6-3 that the execution of mentally retarded persons is prohibited under the Eighth Amendment as cruel and unusual punishment.

Despite his role in a landmark court decision, Daryl Atkins currently resides on Virginia's death row. When the Supreme Court reversed the lower court ruling, it also remanded Atkins' case so that he could be resentenced. After the decision in Atkins, the Virginia legislature passed legislation to define mental retardation. A jury then heard evidence only on the issue of his mental ability. After deliberating 13 hours, and weighing conflicting testimony, the jury concluded that Atkins was not mentally retarded and could, therefore, be sentenced to death. Attorneys for Atkins filed an appeal in October 2005.

In 2005, in another historic decision, the U.S. Supreme Court barred the execution of persons who are under the age of 18 when they commit capital crimes. The ruling in Roper v. Simmons followed the same reasoning used by the Court in Atkins In a 5-4 decision, the majority found that "evolving standards of decency" and the Eighth Amendment's prohibition of cruel and unusual punishment required the banning of juvenile executions. In its reasoning, the court gave credence to the fact that few nations in the world allow the execution of juveniles.