Critics and opponents of the death penalty are warning that capital trials and sentencing hearings are so riddled with flaws that they risk resulting in the execution of innocent persons. Supporters of capital punishment discount the warnings, emphasizing that opponents cannot cite a single person in modern times who was executed and later proven to have been innocent. The debate over erroneous convictions has increased in recent years because DNA testing now allows inmates to prove their innocence years after their convictions. The Supreme Court opens its term on Oct. 3 with two closely watched cases pending on rules allowing state inmates to use newly discovered evidence to challenge their convictions in federal courts, based on “actual innocence” as well as constitutional violations. Meanwhile, death penalty critics want states to follow Illinois' example and impose moratoriums on executions.