Columbia, South Carolina - Richard Moore, a Black man convicted by an all-white jury in South Carolina, was executed Friday for the murder of a convenience store clerk that he claimed was in self-defense, despite widespread calls for clemency.

The 59-year-old was pronounced dead at 6:24 PM local time after receiving a lethal injection at a prison in state capital Columbia, media witnesses said.

Governor Henry McMaster declined to issue a last-minute grant of clemency, ignoring pleas from the former director of the South Carolina Department of Corrections and the judge who presided over Moore's sentencing, among others. The US Supreme Court also refused to intervene.

Moore was sentenced to death in 2001 for the 1999 killing of James Mahoney, a white convenience store clerk, during what prosecutors said was a robbery attempt.

Attorneys for Moore, though, claimed he entered the store unarmed, but got into an argument with Mahoney because he was 11 or 12 cents short of the money needed to make his purchase.

Mahoney allegedly pulled out two guns and Moore wrestled one away, shooting the store clerk to death while being wounded in the arm himself.

According to prosecutors, Moore stole $1,400 and went out to buy crack cocaine. He was arrested soon afterward.

Moore's lawyers said his death sentence was unfair and racially motivated.

"No other South Carolina death penalty case has involved an unarmed defendant who defended himself when the victim threatened him with a weapon," they said in a statement.

The prosecutor "had a history of seeking the death penalty only in cases involving white victims" and rejected all the potential African Americans jurors during jury selection, they added.

South Carolina Senator Josh Kimbrell, a Republican, decried the execution, while Jace Woodrum, Executive Director of the ACLU of South Carolina, called it "a textbook example of the arbitrariness of the death penalty."