1. Why is Warren Hill on death row?

Hill beat a fellow inmate, Joseph Handspike, to death with a nail-studded board in 1990 at a state prison in Leesburg. At the time, Hill was serving a life sentence for the 1986 fatal shooting of his former girlfriend, an 18-year-old woman whom he shot 11 times. Prison authorities said he took the two-by-six board from a bathroom, where it was used to support a sink. He was convicted in the Handspike killing in 1991 and sentenced to death.

2.What is the principle of law at stake in the Hill case? What are people arguing about?

Death penalty defendants sometimes plead “intellectual disability” as a way to show they were not capable of understanding what they did and are therefore not responsible for it. It is illegal in the United States to execute an intellectually disabled inmate. Warren Hill has invoked that defense. But Georgia maintains the highest possible standard of proof among the states that allow the death penalty: here, the defendant must show he or she is intellectually disabled “beyond a reasonable doubt.” Most states use a lesser standard: intellectually disabled by “a preponderance of the evidence” – meaning more likely than not. The difference between the two is the difference between life and death for Hill.  The Vatican, the European Union, Desmond Tutu, the American Bar Association, Jimmy and Rosalynn Carter and others are on record as opposing the execution.

3. What makes Hill’s case stand out?

Two state court judges have found Hill to be intellectually disabled -- but according to the lesser “preponderance of the evidence” standard. In addition, three experts for the state who testified 15 years ago that Hill was not intellectually disabled have since changed their diagnoses. In sworn statements and in interviews with The Atlanta Journal-Constitution, all three said their evaluations were rush jobs and a better scientific understanding leads them to believe Hill is mildly intellectually disabled.

4. Hasn’t he appealed this issue in the courts?

Yes. Here’s a partial timeline:

2002: Superior Court judge in Columbus finds Georgia's strict threshold to be fundamentally unfair because it ensured the state would execute capital defendants who are more likely than not mentally disabled. That judge found Hill to be intellectually disabled by a preponderance of the evidence.

2003: Voting 4-3, the state Supreme Court overturns that judge's ruling. The court finds that exemptions from execution should be granted only to those "whose mental deficiencies are significant enough to be provable beyond a reasonable doubt." The dissenters argued the ruling meant the state may execute inmates who are "almost certainly" intellectually disabled.

2010: A three-judge panel of the federal appeals court in Atlanta, by a 2-1 vote, finds Georgia's standard of proof unconstitutionally increased the risk that an intellectually disabled inmate would be executed.

2011: The entire federal appeals court, by a 7-4 vote, overturns the panel's decision. The court's majority said the state's death-penalty statute contains substantial safeguards to help jurors accurately determine whether a defendant is intellectually disabled.

2012: The U.S. Supreme Court declines to hear Hill's appeal, triggering the scheduling of his execution.

2012: Hill's execution is temporarily stayed amid an argument over Georgia's plans to switch from a three-drug mixture for executions to a single drug. The stay is later lifted and the execution is rescheduled for 2013.

2013: The federal appeals court calls off Hill's execution 30 minutes before it is to take place, saying it would hear arguments about his intellectual ability.

2013: The appeals court rules against Hill.

2014: Hill files a new challenge to the state's intellectual disability law in September in Butts County Superior Court (the county where he is being held on death row). The Butts County court rules against him in October, and his appeals to higher courts fail.

Jan. 27, 2015: The 11th circuit rules against Hill's appeal, saying he has already argued his case on intellectual disability grounds. The state Board of Pardons and Paroles also denies clemency. In a statement, Hill's attorney, Brian Kammer, said, "The clemency board missed an opportunity to right a grave wrong.

5. What are the roots of this argument?

In 1988, Georgia became the first state to ban the execution of the intellectually disabled. Passage of the law is widely attributed to the public outrage that accompanied the 1986 execution of Jerome Bowden, who, before being put to death in the electric chair, had been found to have the mentality of a 12-year-old. In his final statement, Bowden thanked "the people of this institution for taking such good care of me as they have."