John B. Nixon was born on April 1, 1928, in Midnight, Mississippi.

On January 22, 1985, John B. Nixon, along with his son, Henry Nixon, and Gilbert Jimenez, went to the home of Thomas and Virginia Tucker. Once they entered, Nixon showed a .22 caliber pistol and said, "I brought y'all something." Thomas Tucker realized that Nixon and the others had been hired by his wife's ex-husband, Elster Joseph Ponthieux. Thomas offered Nixon money to spare their lives, but Nixon refused, saying, "That's not what I'm after. The deal's already been made."

Nixon and one of his associates shot at Thomas, who was hit in the side but managed to escape. He went to his workplace and asked someone to check on Virginia. Meanwhile, Nixon took the gun back and shot Virginia in the head. After fleeing the scene, Virginia was found and taken to the hospital, where she died the next day. Thomas Tucker later identified Nixon in a lineup, leading to his arrest.

Nixon was convicted of capital murder in March 1986. The jury found that the murder was especially cruel and that Nixon had a history of violent crimes. The man who had hired him received a life sentence, along with two of Nixon's sons and a friend who were also convicted.

During his appeals, Nixon claimed his trial lawyers were not able to represent him properly. They were working on another case and chose not to ask for more preparation time. Nixon's background, including previous acts of heroism, was not mentioned during the trial. A psychiatrist diagnosed him with a personality disorder but said he knew right from wrong when the crime happened.

Nixon's lawyers argued that he was too old to be a danger to society and had been in prison for nearly 20 years. His appeals were denied at several court levels. The Governor of Mississippi, Haley Barbour, denied his clemency request in December 2005, stating that the lengthy delay in justice diminished the death penalty's deterrent effect.

On December 14, 2005, Nixon was executed by lethal injection. He was 77 years old at the time. Officials at the prison described him as cheerful on the day of the execution, although his mood changed as the time approached. While on the gurney, he claimed that he did not kill Virginia Tucker and said it was his son and his associates. For his last meal, he requested a well-done T-bone steak, asparagus, a baked potato with sour cream, and peach pie with ice cream. Before his execution, he shared a statement taken from a folksong.