The precise wording of the question is convoluted, asking jurors “whether there is a probability that the defendant would commit criminal acts of violence that would constitute a continuing threat to society.” At its core, it contains an incredible idea: Can we predict whether or not a killer will kill again?

Meier was one of the key legislators who crafted the law. In the years since, he’s gotten “probably a 100 calls about this” from people asking how he and his colleagues thought it up, he said. But he said he can’t remember the discussion that led to it.

“Imagine trying to remember what you said and did back then,” he said with a chuckle.

Texas holds a unique place in the annals of the American death penalty. It is, by far, the country’s most prolific executioner. Since 1976, when the Supreme Court reinstated the death penalty in a case called Gregg v. Georgia, Texas has executed 538 people. Oklahoma is in second place with a relatively paltry 112 executions. And, more than 30 years later, Meier’s question remains at the heart of this deadly system.

The Supreme Court recently heard arguments in a Texas death penalty case called Buck v. Davis. The defendant, Duane Buck, fatally shot his ex-girlfriend and her friend in July 1995. Two years later, a jury found him guilty and sentenced him to death. The case arrived at the Supreme Court because of a bizarre twist––at the sentencing, Buck’s own lawyer introduced testimony by an expert who said that Buck’s race made him more likely to be a future danger. Buck is black.

Should someone be sentenced to death, in part, because of his race? Should expert witnesses use race to predict whether someone will be violent? Those questions sound shocking, and rightfully so. But the circumstances of Buck’s case––where an expert testified explicitly that race should be a factor for the jury to consider in sentencing––make it an outlier. The framing of the question before the court in Buck’s case is narrow, and doesn’t address whether future dangerousness is the right question to ask.

What if hundreds of people have been sentenced to death using a question aimed at predicting the unpredictable?

I

t’s a tempting notion that we can predict who will live peaceful, productive lives and who will erupt in violence. If we could, it would certainly take some of the arbitrariness out of the death penalty. But how good are we at making those predictions?

The modern age of the death penalty began in 1972. That’s when the Supreme Court heard a Georgia murder case called Furman v. Georgia. The defendant, William Henry Furman, had broken into a home in Savannah and was rummaging around when the homeowner awoke. Furman ran off, but on his way out, he dropped his loaded gun, which fired, killing the homeowner. A jury convicted Furman, who was black, in a one-day trial. In its decision, the Supreme Court held the death penalty, as then applied, was unconstitutional, that it was too haphazardly applied and violated the Eighth Amendment’s prohibition against cruel and unusual punishment.