On the trial for any offense which may be punished capitally or by imprisonment in the penitentiary, it is a good cause of challenge by the state that the person would refuse to impose the death penalty regardless of the evidence produced or has a fixed opinion against penitentiary punishment or thinks that a conviction should not be had on circumstantial evidence, which cause of challenge may be proved by the oath of the person or by other evidence.
Ala. Code § 12-16-152 (1975)