Nikolas Cruz, the lunatic who murdered 17 people at Marjory Stoneman Douglas High School in Parkland, Florida, on Feb. 14, 2018, has escaped the death penalty. The jury found that his crime warranted a death sentence, but also held that other factors mitigated against imposing it in this case. Many of the survivors in the courtroom cried as they realized that the person who showed no mercy to their loved ones would be spared, and I can certainly understand their frustration.

Cases like these, however, are the worst examples for considering whether we should have a death penalty or not. The senseless murder of children is among the least forgivable of crimes, and it’s hard to think of a better case for deterrence than the safety of our nation’s schools. Moreover, their is absolutely not on scintilla of doubt about Cruz’s guilt. Everything lines up here to impose the death penalty without any concern of wrongful conviction or disproportionate justice.

Nonetheless, the argument against the death penalty is mostly about how it functions in totality, not in the easiest cases. People have been put on death row and even executed despite being innocent. Others have avoided the death penalty only through good lawyering that is unavailable to those without a lot of resources. The only way to assure that these types of problems don’t persist is voluntarily forego the death penalty for all crimes. A wrongful conviction can be overturned, but it’s meaningless if the victim has been executed.

In Florida, a death penalty sentence requires unanimity from the jury, and at least one juror refused to go along in the Parkland case, presumably because they found the defense’s plea for mercy persuasive.

In laying out their defense, lawyers for Cruz presented testimony from counselors and a doctor who say the defendant suffers from a fetal alcohol spectrum disorder, a condition that they argued affects his reasoning and behavior. Witnesses testified that his birth mother, Brenda Woodard, had abused alcohol and cocaine while she was pregnant with him.

“You now know that Nikolas is a brain-damaged, broken, mentally-ill person, through no fault of his own,” Cruz’s lawyer, Melissa McNeil, stated in closing arguments. “He was literally poisoned in Brenda’s womb.”

Maybe it was simply death penalty-nullification. The jurors all agree pre-trial that they would follow the law, not their personal beliefs, in imposing a sentence. But maybe someone lied about that.

Or maybe they thought Cruz was somehow not responsible. Personally, I have mixed feelings. Cruz doesn’t deserve to live. We shouldn’t have to pay for his upkeep. But every time a death penalty case fails, for whatever reason, it’s a good thing. And I do think it’s a double-edged sword. Life in prison is no picnic, and death can be an easy way out. If Cruz has any conscience at all, spending decades behind bars will give him plenty of time to suffer from guilt. And, if not, he’ll suffer from confinement and the other depredations of imprisonment.

Some of the parents who are traumatized anew by this verdict may look back later and be grateful. Through their testimony and impact statements, they fought to end someone’s life. But since they failed, unlike Cruz, they will never have that on their conscience. And Cruz will have no rest.