DOVER — Should being sentenced to death under provisions later found to be unconstitutional be grounds to overturn that death sentence?

That’s the question Delaware’s top judges are being asked to answer. It’s an issue that could have broad implications in potentially re-affirming or overruling convictions for the 13 men now on the state’s death row.

Lawyers debated for 50 minutes Wednesday’s before the state’s top court, attempting to sway justices in the case of Derrick Powell.

Powell, now 29, was sentenced to death in 2011 for killing Georgetown police officer Chad Spicer in 2009. But earlier this year, the state Supreme Court ruled aspects of Delaware’s capital punishment law were unconstitutional and struck it down.

The ruling, in Rauf v. State, did not address the 13 men on death row. However, it led to lawyers for Powell filing an appeal.

Arguing for the defense Wednesday, Patrick Collins said the August ruling that struck down the death penalty is a “substantive” change.

“This court’s decision in Rauf recognized that every fact necessary to impose a death penalty must be found unanimously, beyond a reasonable doubt and by a jury,” he told justices. “Because Derrick Powell’s sentence had none of those constitutional protections, we ask this court to vacate his sentence of death.”

Deputy Attorney General John Williams countered that the state had used rules set down by the federal Teague v. Lane case to determine retroactivity, under which the Powell appeal did not fit.

Several justices appeared skeptical of the prosecution’s claims with Chief Justice Leo Strine leading questioning. The chief justice posed to Mr. Williams several queries that indicated he appeared to disagree with his argument.

“Are you saying … that it’s essentially almost as a fraud on the American public in the U.S. Supreme Court, that they have a prong of a test which can never actually be satisfied?” Chief Justice Strine asked.

In court filings, the state said it would not be in the best interest of the legal system to throw out the death sentence, arguing the system would be hindered by the potential for continued appeals.

Mr. Williams followed up on that argument, saying “litigation should not just proceed endlessly.”

Four of the five justices asked questions Wednesday with James Vaughn silent. Although they challenged both sides, several justices appeared to be leaning toward the defense’s claims.

Three of the five members of the Supreme Court ruled in favor of striking down the death penalty in August. The fourth agreed with them on some points but differed on others.

Asked by the court what the outcome would be if the case was judged to be based on a “procedural” change rather than “substantive,” Mr. Collins replied Mr. Powell still could not be executed.

“This court’s point in Rauf that a person has the right to not be executed unless a unanimous cross-section of the community believes that should be the case stands … as a fundamental watershed procedural right that the defendant has, if we’re going to call it procedural,” he said.

But Justice Collins Seitz delivered the most concise statement during the hearing.

“How could it ever be just to execute someone who was sentenced under a flawed statute?” he asked.