In my last column, I analyzed the question of what relevance the humane killing of pet animals might have for assessing the constitutionality of execution by lethal injection - the method of capital punishment now facing a challenge before the U.S. Supreme Court in Baze v. Rees. In this column, I ask, and suggest answers to, a somewhat different question. The U.S. Constitution requires that if we impose the death penalty on a convicted criminal, we do so in a manner that is humane and that does not cause unnecessary pain or torment. On that test, the ...