Even a plea from Pope Francis could not save Kelly Renee Gissendaner.
The Georgia woman whose case drew a call for mercy from the pontiff was executed at 12:21 a.m. Wednesday after a flurry of last-minute appeals failed.
She sang "Amazing Grace" before dying, according to witnesses.
Gissendaner was sentenced to death for the 1997 stabbing murder of her husband at the hands of her lover, who got life in prison for the crime.
She was the first woman executed in Georgia in 70 years and one of a handful of death-row inmates who were executed even though they did not physically partake in a murder.
The mother of three was nearly executed in February, but the lethal injection was abruptly called off because the chemicals appeared cloudy.
After a new execution date was set, Gissendaner, 47, convinced the Georgia Board of Pardons and Paroles to reconsider her application for clemency.
In an extraordinary turn, Pope Francis -- who called for a global ban on the death penalty during his U.S. visit last week -- urged the board to spare her life.
"While not wishing to minimize the gravity of the crime for which Ms. Gissendander has been convicted, and while sympathizing with the victims, I nonetheless implore you, in consideration of the reasons that have been expressed to your board, to commute the sentence to one that would better express both justice and mercy," Archbishop Carlo Maria Vigano wrote on the pontiff's behalf.
Shortly thereafter, the board announced that it would not stop the execution.
The victim's family was split on whether Gissendaner should live or die: Her children appeared before the parole board to ask that their mom be spared the death chamber, but her husband's relatives said she did not deserve clemency.
"Kelly planned and executed Doug's murder. She targeted him and his death was intentional," Douglas Gissendaner's loved ones said in a written statement.
"In the last 18 years, our mission has been to seek justice for Doug's murder and to keep his memory alive. We have faith in our legal system and do believe that Kelly has been afforded every right that our legal system affords.
"As the murderer, she's been given more rights and opportunity over the last 18 years than she ever afforded to Doug who, again, is the victim here. She had no mercy, gave him no rights, no choices, nor the opportunity to live his life. His life was not hers to take."
In the hours before her death, Gissendaner sought stays of executions on a number of fronts, claiming it was not fair she got death while her lover didn't, that the execution drugs might be defective, and that she had turned her life around and found religion while in prison.
She requested her final meal last week: cheese dip with chips, Texas fajita nachos and a diet frosted lemonade.
Additional reporting by Gabe Gutierrez.
This article originally appeared on NBC News.com. This is a developing story, please check back here for more updates.