Stanley Williams III, known to many as “Tookie”, was a notorious career criminal. A founding member of the West Side Crips gang in Los Angeles, from 1971 he embarked on an eight-year rampage of brutality, culminating in his conviction for the murders of four men in 1979. Once incarcerated, he assaulted other inmates and guards, and spent six years in solitary confinement.

Yet somewhere along the line, something changed in Tookie Williams. He renounced his past, and his life of violence. He became a voice against gang culture and the crippling effect it was having on American youth, especially on young black boys. He became a distinguished author on the subject, publishing twelve volumes.

In 2005, he was executed by the State of California by lethal injection.

Whether or not Tookie Williams really was reformed was questioned by the state as a reason for not granting him clemency. Yet he is not the only example of convicted criminals rehabilitating themselves, having once seemed completely beyond redemption. Take the case of mass killer Clayton Fountain, who became a priest, or Auckland murderer Paul Wood, who become one of several prisoners to earn a PhD while behind bars.

It seems such a shame that a country which counts itself as one of the most civilised in the world would put to death a human being – any human being – who retained the capacity to turn their lives around for good, even with no chance of release from prison. It does happen, even to the most hardened and seemingly callous of men.

Which brings us to Dylann Roof.

USA: Church shooting survivor gives emotional statement to Dylann Roof in court

As mass shootings go, there was something particularly shocking about Roof’s crimes. To walk into a church and be welcomed by the congregation, to sit with them while they prayed, and then to shoot them, repeatedly, at close range, as their meeting entered what was for them was its most sacred moment, is incomprehensible for most people. To have done it because those innocent victims happened to be black makes it even more incomprehensible. It’s not hard to see why America might be clamouring for him to be executed.

Yet I hope he isn’t.

While Roof has appeared emotionless and unapologetic, his actions were met with an outpouring of emotion – overwhelmingly grief, of course, but also, remarkably, forgiveness. During his trial, we witnessed as a relative of one of his victims professed her forgiveness to him over and over through her sobs. Throughout the trial, indeed, no relative of any of the victims ever asked for the death penalty. It would have been understandable had they done so, and they were entitled to do so – but no one did.

Such grace, even in the face of such reckless hatred, was praised by Barack Obama, in what has become one of the iconic moments of his presidency, when he sang the first verse of the hymn Amazing Grace at a funeral for the victims.

Activists protest the death penalty in Texas Show all 6 1 /6 Activists protest the death penalty in Texas Activists protest the death penalty in Texas Family and friends of Jeff Wood and anti-death penalty activists march from the Texas State Capitol to the Office of Governor Greg Abbott to deliver a petition with over 10,000 signatures asking the governor and the Texas Board of Pardons and Paroles to commute Wood's sentence on August 18, 2016 in Austin, Texas. Jeff Wood is scheduled to be executed by the state of Texas on August 24, 2016 under what is referred to as the "law of parties" for a criminal act he committed on January 2, 1996. The Texas law says that if a person, " acting with intent to promote or assist the commission of the offense, he solicits, encourages, directs, aids, or attempts to aid the other person to commit the offense;" then they are criminally responsible for the conduct of another, as well. Tamir Kalifa/AFP/Getty Images Activists protest the death penalty in Texas Carla Harvey adds her name to a petition with over 10,000 signatures asking Governor Greg Abbott and the Texas Board of Pardons and Paroles to commute Jeff Wood's sentence, during a demonstration outside of the Texas State Capitol on August 18, 2016 in Austin, Texas. Family and friends of Jeff Wood and anti-death penalty activists delivered the petition to the Office of the Governor after the demonstration. Jeff Wood is scheduled to be executed by the state of Texas on August 24, 2016 under what is referred to as the "law of parties" for a criminal act he committed on January 2, 1996. The Texas law says that if a person, " acting with intent to promote or assist the commission of the offense, he solicits, encourages, directs, aids, or attempts to aid the other person to commit the offense;" then they are criminally responsible for the conduct of another, as well. Tamir Kalifa/AFP/Getty Images Activists protest the death penalty in Texas A massive explosion guts Mexico's biggest fireworks market in Mexico City, on December 20, 2016. The explosion killed at least 31 people and injured 72, authorities said. The conflagration in the Mexico City suburb of Tultepec set off a quick-fire series of multicolored blasts that sent a vast cloud of smoke billowing over the capital. Tamir Kalifa/AFP/Getty Images Activists protest the death penalty in Texas Darius Broussard adds his name to a petition with over 10,000 signatures asking Governor Greg Abbott and the Texas Board of Pardons and Paroles to commute Jeff Wood's sentence, during a demonstration outside of the Texas State Capitol on August 18, 2016 in Austin, Texas. Family and friends of Jeff Wood and anti-death penalty activists delivered the petition to the Office of the Governor after the demonstration. Jeff Wood is scheduled to be executed by the state of Texas on August 24, 2016 under what is referred to as the "law of parties" for a criminal act he committed on January 2, 1996. The Texas law says that if a person, " acting with intent to promote or assist the commission of the offense, he solicits, encourages, directs, aids, or attempts to aid the other person to commit the offense;" then they are criminally responsible for the conduct of another, as well. Tamir Kalifa/AFP/Getty Images Activists protest the death penalty in Texas Family and friends of Jeff Wood and anti-death penalty activists march from the Texas State Capitol to the Office of Governor Greg Abbott to deliver a petition with over 10,000 signatures asking the governor and the Texas Board of Pardons and Paroles to commute Wood's sentence on August 18, 2016 in Austin, Texas. Jeff Wood is scheduled to be executed by the state of Texas on August 24, 2016 under what is referred to as the "law of parties" for a criminal act he committed on January 2, 1996. The Texas law says that if a person, " acting with intent to promote or assist the commission of the offense, he solicits, encourages, directs, aids, or attempts to aid the other person to commit the offense;" then they are criminally responsible for the conduct of another, as well. Tamir Kalifa/AFP/Getty Images Activists protest the death penalty in Texas Mark Clements (L), who was imprisoned for 28 years before being released and exonerated, encourages passersby to sign a petition with over 10,000 signatures asking Governor Greg Abbott and the Texas Board of Pardons and Paroles to commute Jeff Wood's sentence, during a demonstration outside of the Texas State Capitol on August 18, 2016 in Austin, Texas. Clements joined family and friends of Jeff Wood and anti-death penalty activists to deliver the petition to the Office of the Governor after the demonstration. Jeff Wood is scheduled to be executed by the state of Texas on August 24, 2016 under what is referred to as the "law of parties" for a criminal act he committed on January 2, 1996. The Texas law says that if a person, " acting with intent to promote or assist the commission of the offense, he solicits, encourages, directs, aids, or attempts to aid the other person to commit the offense;" then they are criminally responsible for the conduct of another, as well. Tamir Kalifa/AFP/Getty Images

It is forgiveness, and the chance to start again and find redemption, which is at the heart of the Christian faith, along with the understanding that vengeance – which is what the death penalty is – is reserved for the wrath of God alone. Forgiveness, though, has sadly become a rarity, and vengeance, both from the state and individuals, is all the rage.

Yes, Dylann Roof is a vile creature whose crimes are abhorrent. Even so, his victims and those closest to them have forgiven him, and though many would love to see him die, there would probably be no greater outcome for the families than the chance for this person to come to an understanding of how wicked his acts really were, and to ultimately feel remorse.

Keeping someone incarcerated for the rest of their lives is expensive, and allows murderers to live lives that their victims were so cruelly denied. But we cannot consider society truly forward-facing if, instead of punishment and rehabilitation, justice systems are based on taking revenge against citizens.