I am against the death penalty as a punishment for most crimes, however some crimes are so heinous that they literally demand the death penalty. Crimes such as: treason, genocide, mass murder, mass or multiple rape, killing or rape of a child, assassination of a government official or a police officer, killing a kidnap victim, killing a witness to a crime, killing in the furtherance of another crime, and soldiers deliberately targeting and killing innocent noncombatants should all be eligible for the death penalty.
However the death penalty should be subject to very strict requirements, procedures and oversight, such as the state should have to present a valid non-coerced confession that has not been recanted and evidence supporting the confession must be presented. Or if a confession is not available the state must present: both testimony and scientific evidence that clearly and positively proves that the defendant is guilty beyond any reasonable doubt, and that the defendant is and was at the time of the crime mentaly competent, and that the defendant at the time of the crime was of the age of reason, and that the defendant acted with malice and aforethought, and that the defendant had adequate legal representation during his trial and appeals for his defense.
In implementing the death sentence the state should be required to use as humane a method as possible.