A key safeguard of citizens' rights in the criminal justice system is the adversarial nature of the criminal trial, where the defense and prosecution each advocates for its own interests. But what happens when that adversarial relationship collapses and a defense attorney advances the prosecution's argument, rather than the one his client asks him to present?

On January 17, 2018, the U.S. Supreme Court will hear oral argument in McCoy v. Louisiana, a case that will determine whether the law allows a defense attorney to concede a defendant's guilt to the jury over the defendant's explicit objections. As a student of the U.S. Constitution, I believe the answer is “no.”

About two weeks before his capital trial in Louisiana, Robert McCoy learned that his lawyer planned to act against his clear wishes and tell the jury that he was guilty of murder, in the hope of persuading the jury to impose a sentence less than death. McCoy repeatedly told his attorney and the trial court before trial that he wanted to maintain his innocence and hold the prosecution to its burden of proving its case beyond a reasonable doubt. But the court and the defense attorney ignored McCoy's objections.

McCoy asked the trial court to terminate his lawyer because he was working against him, but the court denied McCoy's request. At trial, over McCoy's express objection, the court permitted defense counsel to tell the jury that his client committed the murders, and to state categorically: “I've just told you he's guilty.”

Having proclaimed his client's guilt, McCoy's lawyer doubled down during his closing argument and stated he had removed the burden of proof from the prosecution.

The Supreme Court of Louisiana should have corrected these stunning errors. Neither counsel nor the trial court had the authority to obliterate the presumption of innocence. By telling the jury McCoy was guilty, over McCoy's repeated objection, defense counsel failed to act as his client's advocate and denied his client's autonomy within the criminal justice system. When McCoy's attorney decided unilaterally to concede the government's charges against his client, he stripped McCoy of his constitutionally mandated due process and fair trial rights.

Under the Sixth Amendment, the ultimate decision whether to maintain his innocence and hold the prosecution to its burden of proof belonged to Mr. McCoy alone. Once Mr. McCoy made that decision and expressed his objections, his lawyer could not constitutionally override that decision on his own accord. The lawyer may choose the means to carry out his client's defense, but he cannot ignore his client's core decisions in his own case.

An important way to understand the Constitution's Bill of Rights is to consider the framers' experience at the time these rights were debated and adopted. In England in the mid-eighteenth century, the law required a defendant to personally enter a plea, and only the defendant could argue the case to the jury. In most of the trials of the late 1700s, defendants represented themselves. The Sixth Amendment's guarantee of the assistance of counsel was adopted at a time when lawyers were just beginning to appear for the defense in England.

As time went by, in both Britain and the United States, attorneys took on greater roles, but defendants never lost the central decision-making role in their own defense. Criminal defendants must be free to determine the objectives of their defense, and to define their own best interests. The attorney must honor the decision to maintain one's innocence or to plead guilty, and act as a representative with respect to either choice. The Framers of the Constitution would have unambiguously understood that the Sixth Amendment forbids attorneys from incriminating their own clients against the client's express objection, and in pursuit of an objective that conflicts with the client's clear directive.

As a former prosecutor and appellate judge, it is hard for me to imagine a criminal proceeding more fundamentally unfair than McCoy's. The trial suffered a structural error so intrinsically damaging that it demands reversal. The constitutional deprivation of McCoy's rights was not simply a process error, but one that undermined the adversarial framework on which our system is based.

The core constitutional principle that each defendant has the right to decide whether to admit or contest guilt before the jury must be protected. The U.S. Supreme Court should take this opportunity to do so.

Tim Lewis, a former prosecutor and federal district court judge, was appointed by President George H. W. Bush to the U.S. Court of Appeals for the Third Circuit (1992–1999). He is currently co-chair of Schnader Harrison Segal & Lewis's ADR Practice Group.