Like so many Americans, I have found myself in recent years on a journey when it comes to capital punishment.

I used to be an ardent supporter of the death penalty. Twenty years ago, I would have confidently argued that the only reason there is any doubt about the deterrent effect of capital punishment is that we execute too few murderers and do so too slowly. I would have waved away any anecdote about innocent people being released from death row by saying something like, "The fact that someone who was not guilty did not die is not an argument against capital punishment."

But the number of innocent people freed from death row — at 156 and climbing, according to the anti-capital punishment Death Penalty Information Center — rose to the point where I began to feel doubt. Other concerns also gnawed at me. I am both pro-life and substantially libertarian in my politics, combining a belief in the sanctity of human life and a skepticism of government power that sits uneasily with support for capital punishment.

I no longer believe in executions as a routine punishment for the worst crimes, even homicide. The criminal justice system is too flawed and in need of reform. Too few Americans, especially in communities of color, have confidence in the equal protection of our laws.

Yet my journey has not ended at the same destination as others who have raised similar questions about the death penalty. I still do not believe capital punishment is inherently unjust in principle, even if I believe its frequent application is always likely to become so in practice. And some crimes are so heinous, there is no other just punishment for them.

For an example, look no further than the trial of Dylann Roof. Roof has confessed to murdering nine innocent Americans during a prayer service at a historic black church in Charleston, South Carolina. He killed them in cold blood while they prayed, in premeditated fashion, because of the hatred burning in his heart.

Many of the common objections to the death penalty do not apply in Roof's case. There is no doubt about his guilt. "I went to that church in Charleston and I did it," he confessed with a laugh. "Did you shoot them?" a law enforcement officer asked. "Yes," Roof replied, laughing again.

Sentencing Roof to death would not illustrate structural racism. Quite the opposite. It would enhance racial justice and signify progress in a region of the country where the state did not always protect African Americans from racist murderers. It would be a public affirmation that black lives matter.

Wielding the noose infrequently makes its occasional uses a more powerful statement of our society's intolerance of certain acts of evil without allowing it to devalue life itself. Consider the countries that do not normally have the death penalty but executed Nazi war criminals. Osama bin Laden's death would have been an act of justice even if he could have been apprehended peacefully.

Murder is a gruesome and barbaric business. Its perpetrators deserve the ultimate punishment. But a society must try to balance its power and right to impose that penalty with its need to avoid becoming an accomplice to murder itself.

That's admittedly not an easy balance to reach. One of the other cases that has kept me from becoming an unadulterated opponent of the death penalty is the murder of a friend's grandmother. A sweet 94-year-old woman, she was brutally beaten to death by a young man who robbed and attempted to rape her in her own home.

The poor woman had lived nearly ten decades in peace, seeking only to live out the rest of her days with dignity. Instead her life ended in violence and terror. No other punishment seems adequate for such a crime, even though the perpetrator is not eligible for capital punishment under current legal precedent due to his age, a teenager being tried as an adult.

It is possible so many outrageous cases could be found that if we imposed death sentences in all of them, we would quickly be back to our current system of mass executions. Even in Roof's case, it feels wrong to write about how his crimes warrant capital punishment with Christmas music playing in the background, hours removed from church.

But that might be exactly what the country needs: a reluctant hangman carefully guarding their occasional acts of justice against degenerating into injustice.