The chief justice said yes. “It’s a day that’s here,” he said, “and it’s putting a significant strain on how the judiciary goes about doing things.” He appeared to be referring to software used in sentencing decisions.

That strain has only increased, the chief justice wrote on Sunday.

“In criminal cases, the use of A.I. in assessing flight risk, recidivism and other largely discretionary decisions that involve predictions has generated concerns about due process, reliability and potential bias,” he wrote. “At least at present, studies show a persistent public perception of a ‘human-A.I. fairness gap,’ reflecting the view that human adjudications, for all of their flaws, are fairer than whatever the machine spits out.”

Chief Justice Roberts concluded that “legal determinations often involve gray areas that still require application of human judgment.”

“Judges, for example, measure the sincerity of a defendant’s allocution at sentencing,” he wrote. “Nuance matters: Much can turn on a shaking hand, a quivering voice, a change of inflection, a bead of sweat, a moment’s hesitation, a fleeting break in eye contact. And most people still trust humans more than machines to perceive and draw the right inferences from these clues.”

Appellate judges will not soon be supplanted, either, he wrote.

“Many appellate decisions turn on whether a lower court has abused its discretion, a standard that by its nature involves fact-specific gray areas,” the chief justice wrote. “Others focus on open questions about how the law should develop in new areas. A.I. is based largely on existing information, which can inform but not make such decisions.”