As long as you have capital punishment there is no guarantee that innocent people won’t be put to death.

Paul Simon’s remark frames opposition to the death penalty as a problem of irreversible error rather than (or in addition to) moral theory. The claim is probabilistic and institutional: because criminal justice systems are fallible—dependent on evidence, testimony, policing, and legal representation—wrongful convictions can occur, and execution makes those mistakes permanent. The quote thus shifts the burden onto proponents of capital punishment to justify a sanction that cannot be remedied once carried out. It also implicitly endorses alternatives (life imprisonment, parole restrictions) that preserve the possibility of correction when new evidence emerges.