The Supreme Court. (Ricky Carioti/The Washington Post)

The Supreme Court on Wednesday said a Texas death-row inmate deserves another chance at securing funds for evidence that might lead to a reconsideration of his sentence.

The justices were unanimous in ruling that the U.S. Court of Appeals for the 5th Circuit was too restrictive in reading a federal law that allows indigent defendants to secure money for “investigative, expert or other services.”

The federal Criminal Justice Act allows lawyers to receive such funds when it is “reasonably necessary” to assemble the kind of mitigating evidence that might persuade the jury to forego a sentence of death.

But a judge denied the funds to attorneys for Carlos Manuel Ayestas, who was convicted of the killing of 67-year-old Santiaga Paneque during an invasion of her Houston home in 1995.

In the 5th Circuit, which covers Texas, Louisiana and Mississippi, the law has been interpreted to mean a defendant must show that there is a “substantial need” for such services.

Ayestas’s attorneys said that created something of a Catch-22: The defendant would have to demonstrate that there is some relevant evidence he could discover without first having the funding to pursue that evidence.

Justice Samuel A. Alito Jr. said the appeals court was wrong to impose the “substantial need” standard.

Ayestas “contends that this interpretation is more demanding than the standard — “reasonably necessary” — set out in the statute,” Alito wrote. “And although the difference between the two formulations may not be great, petitioner has a point.”

Courts deciding whether to grant the funds — Ayestas’s attorneys asked for $20,000 — must consider the potential merit of the claims a petitioner wants to pursue, the likelihood that something beneficial might be obtained and whether the petitioner would be able to clear any procedural hurdles to presenting the mitigating evidence.

Ayestas wants to show that his previous attorneys provided ineffective counsel, because they did not present a fuller portrait of his life that might spare him from execution. They contend he has been diagnosed with schizophrenia and was a regular user of cocaine and alcohol at the time of what Justice Ruth Bader Ginsburg at oral arguments called a “horrific” killing.

The case returns to lower courts so that they can judge Ayestas’s request under the proper standard.

Justice Sonia Sotomayor, joined by Ginsburg, thought that step was unnecessary.

“On the record before this court, there should be little doubt that Ayestas has satisfied” the standard, Sotomayor wrote.

The case is Ayestas v. Davis.

The court also ruled for the defendant in a second case decided Wednesday.

The justices ruled 7 to 2 that, for someone to be convicted of obstructing the work of the Internal Revenue Service, a person must be aware that he or she is under investigation or should have known that was a reasonable possibility.

The decision, written by Justice Stephen G. Breyer, makes it more difficult for the federal government to obtain convictions under an omnibus section of the tax law.

Justices Clarence Thomas and Alito disagreed with their colleagues’ interpretation of the law.

The case is Marinello v. United States.