Unsurprisingly, a jury convicted Panetti of murder. After calling only one witness—his stand-by counsel—at the penalty phase of his trial, the jury sentenced Panetti to death after only one day of deliberation.

As with many individuals on death row, a long series of appeals followed, focusing on Panetti’s mental illness. In October, the U.S. Supreme Court denied Panetti’s petition for review, and Texas courts have thus far declined to grant a stay of execution to allow time for an assessment of his competency for execution. Panetti has not received a competency evaluation in nearly seven years.

No one could dispute that Panetti’s actions were atrocious beyond words. The death of two innocent people is an unspeakable tragedy. But the execution of a man grievously afflicted by mental illness for three decades would in no way compensate for the murder of his in-laws.

The U.S. Supreme Court, in a 1986 case called Ford v. Wainwright, prohibited the execution of people who are so out of touch with reality that they do not know right from wrong and cannot understand their punishment or the purpose of it. Panetti’s attorneys argue that this holding applies to him. His severe mental illness causes him to believe that Satan, working through the state of Texas, is seeking to execute him for preaching the Gospel—and, therefore, he cannot possess a rational understanding of the link between his crime and his punishment. To most people, Panetti’s lengthy history of mental illness and his bizarre behavior strongly suggest that Ford should prevent his execution. Yet in practice, Ford’s guarantee is often compromised when courts refuse to order mental health evaluations in a timely fashion, as Panetti’s seven years without a competency evaluation illustrate all too clearly.

His imminent execution reveals just one of many reasons the death penalty in its current form is profoundly flawed. Across the country, the death penalty is administered in a wildly arbitrary way among offenders who have committed similar crimes. For example, one of us found in recent research that while the death penalty was an option in approximately 92 percent of all first-degree murders during one decade in Colorado, it was sought by the prosecution in only three percent of those killings and obtained in only 0.6 percent of cases. And Colorado is hardly unique. Justice administered so unevenly is no justice at all.

Likewise, the recent botched executions of Clayton Lockett in Oklahoma and Joseph Wood in Arizona show that the methods of execution are both cruel and unusual. Executioners lack basic training, shortages of drugs previously used in executions have led states to experiment with different lethal injection cocktails, and courts have prevented attorneys for those sentenced to die from accessing information about the details of an upcoming execution.