Obstacles to carrying out the death penalty are mounting, keeping the number of executions conducted in the United States low, experts say. Only a few of the 31 states where capital punishment remains legal still put prisoners to death. And the decision in May by one of the world’s top pharmaceutical companies to prohibit its drugs from being used in executions placed another hurdle in the way of states that allow capital punishment. To use lethal injections, states must now obtain substitute drugs from compounding pharmacies that want their identities kept secret. The constitutionality of Florida’s death penalty sentencing procedures also is being challenged, presenting yet another obstacle to capital punishment. Alongside all of these legal and logistical conflicts, the fundamental question of the morality of the death penalty remains hotly contested.