Yet, in practice, whether or not persons who are mentally ill or who suffer from extremely limited mental competence escape the death penalty depends a great deal upon the availability of expert psychiatric testimony to use in their defence.
然而，在实践中，患有精神病或智力极为有限的人是否能逃避死刑，在很大程度上取决于其辩护中有没有精神病专家的证词。