A basic tenet of our system of justice is that every person facing criminal prosecution in America—whether rich or poor—deserves competent legal representation. That tradition is especially important for those facing the ultimate punishment when the quality of one’s lawyer and the availability of resources for that representation can determine who lives and who dies. In a case before the U.S. Supreme Court this month, the State of Texas asks the high court to reject this fundamental norm of our legal system.

The case centers on whether attorneys for a man on Texas’s death row, Carlos Ayestas, should be afforded the legal resources, such as an investigator, needed to examine their client’s background and mental health history in federal court. In short, because Ayestas is indigent, a federal district court in Texas has placed him in a Catch-22: He cannot afford to pay for his own investigator, so the court has ruled that he must first prove what an investigator would uncover in order to approve funding to hire that investigator in the first instance. And Texas is defending that decision at the U.S. Supreme Court this month.

To make matters worse, Mr. Ayestas now needs court approval for these resources only because Texas failed to provide him with an adequate lawyer when it mattered most: at trial. At his death penalty trial in state court, Ayestas’ court-appointed counsel did virtually nothing to investigate his client’s background and mental health. As a result, his lawyers presented only two minutes of mitigation evidence at the punishment phase of his trial. The jury then determined he should be sentenced to death — an unsurprising result given the paltry case for life made by the defendant’s own attorneys.

After his opportunity for introducing new evidence in state court lapsed, Mr. Ayestas was finally seen by a mental health professional and was diagnosed with schizophrenia. New lawyers learned that his trial counsel failed to investigate his background and mental health despite knowing that he had multiple head traumas and a history of substance abuse.

Even more alarming is the State’s primary rationale for now objecting to Mr. Ayestas’ request for funding: Texas asserts that it is too costly. Setting aside that Mr. Ayestas is not seeking exotic or expensive services, the State’s rationale is even more indefensible in light of Texas’ role in failing to provide adequate representation at trial, which would have obviated the need for a federal court to now consider the short-comings of the state proceedings. Mr. Ayestas is not seeking platinum justice; he just wants his lawyers to have the basic tools they need to represent him — tools which have been denied to him only because he is poor.

There is no denying that the crime Mr. Ayestas was convicted of is worthy of punishment. But if Texas had provided him with adequate trial counsel, the jury would have likely heard substantial evidence that would have recommended against a death sentence. If the death penalty is to be reserved for the “worst of the worst,” Mr. Ayestas has been deprived of a fair opportunity to show that he does not belong to that group. The Supreme Court should not compound that error.

Timothy K. Lewis was a judge on the United States Court of Appeals at the Third Circuit and is currently Of Counsel for Schnader Harrison Segal & Lewis LLP. He also serves as Co-Chair of The Constitution Project’s National Right to Counsel Committee, which filed an amicus brief in Ayestas v. Davis.