Argued before the Supreme Court in 1992 and decided in a contentious 6-3 ruling in 1993, Herrera v. Collins states
that anyone who is found legally guilty in a court of law, even if later evidence determines that they are actually innocent, does not have explicit constitutional protection under the 8th amendment's wording on cruel and unusual punishment.
In his spirited dissenting opinion, Justice Blackmum, joined by Justices Stevens and Souter, stated:
"Nothing could be more contrary to contemporary standards of decency or more shocking to the conscience than to execute a person who is actually innocent."
Chastising the majority for its circumspection, Blackmun wrote, "We really are being asked to decide whether the Constitution forbids the execution of a person who has been validly convicted and sentenced, but who, nonetheless, can prove his innocence with newly discovered evidence," and he took note of "the State of Texas' astonishing protestation to the contrary."
What could be more cruel and unusual than executing an actually innocent person?
While it appears that modern thinking about the meaning of "cruel and unusual" is focused on the actual methods of execution, the gentlest method of execution for someone who is actually innocent is the gravest form of injustice and cruelty possible.
With 325 convicted people in America now exonerated of guilt by DNA evidence alone, it's essential that those who are legally found guilty in our country are given every opportunity to prove their actual innocence. Regardless of cost or convenience, if new evidence, post conviction, is likely to have influenced the outcome of a case, it must be considered.