NASHVILLE — Until August, Tennessee had not put a prisoner to death in nearly a decade. Last Thursday, it performed its third execution in four months.

This was not a surprising turn of events. In each case, recourse to the courts had been exhausted. In each case Gov. Bill Haslam, a Republican, declined to intervene, though there were many reasons to justify intervening. Billy Ray Irick suffered from psychotic breaks that raised profound doubts about his ability to distinguish right from wrong. Edmund Zagorksi’s behavior in prison was so exemplary that even the warden pleaded for his life. David Earl Miller also suffered from mental illness and was a survivor of child abuse so horrific that he tried to kill himself when he was 6 years old.

Questions about the humanity of Tennessee’s lethal-injection protocol were so pervasive following the execution of Mr. Irick that both Mr. Zagorski and Mr. Miller elected to die in Tennessee’s electric chair, which was built in 1916. (The state spruced it up in 1989.) Their choice says something very clear about Tennessee’s three-drug execution cocktail, as Justice Sonya Sotomayor noted in a dissenting opinion to the Supreme Court’s decision not to hear Mr. Miller’s case: “Both so chose even though electrocution can be a dreadful way to die,” she wrote. “They did so against the backdrop of credible scientific evidence that lethal injection as currently practiced in Tennessee may well be even worse.” Electrocution might not be any more humane than death by lethal injection, in other words, but at least it offers a speedier hideous death.

Presumably this is the same thinking behind the position taken by 51 death-row prisoners in Alabama who want to die in an untested nitrogen gas chamber rather than by either the electric chair or lethal injection.