“The impartiality of a defendant’s trial and conviction must be beyond reproach,” Mr. Abbott said. “Thus, before the state carries out the ultimate, irreversible punishment, the appropriate trial court should thoroughly review this matter.”

The convicted murderer, Charles D. Hood, 39, is scheduled to be executed on Wednesday for the murder and robbery in 1989 of a couple he lived with in Plano, just north of Dallas.

Fingerprints linked Mr. Hood to the murders, and he was arrested the next day in Indiana driving a car belonging to the murdered man, Ronald Williamson, who had been Mr. Hood’s supervisor at a strip club where they both worked. Mr. Williamson’s girlfriend, Tracie Lynn Wallace, a former dancer at the club, was also killed.

Having exhausted all other appeals, Mr. Hood’s lawyers have tried to prove in recent months that Mr. Hood’s trial in 1990 was tainted because the judge, Verla Sue Holland, and the Collin County district attorney at the time, Thomas S. O’Connell Jr., were having an affair.

Photo

Neither Judge Holland, who is retired, nor Mr. O’Connell, who is in private practice, returned calls seeking comment.

Lawyers for Mr. Hood contend that the affair, first reported in 2005 in the online magazine Salon, was long rumored in Collin County’s legal circles, but no one with evidence about it had been willing to testify under oath.

“It’s a wall of silence we have been trying to break down,” said Greg Wiercioch, one of Mr. Hood’s lawyers.

Newsletter Sign Up Continue reading the main story Please verify you're not a robot by clicking the box. Invalid email address. Please re-enter. You must select a newsletter to subscribe to. Sign Up You will receive emails containing news content , updates and promotions from The New York Times. You may opt-out at any time. You agree to receive occasional updates and special offers for The New York Times's products and services. Thank you for subscribing. An error has occurred. Please try again later. View all New York Times newsletters.

In June, Mr. Hood’s lawyers got a sworn affidavit from a former assistant district attorney, Matthew Goeller, who said the romantic relationship “was common knowledge in the district attorney’s office, and the Collin County bar, in general,” at the time of the trial. Mr. Goeller said the affair was going on when he came to the office in 1987 and continued through 1993.

Advertisement Continue reading the main story

With this testimony in hand, Mr. Hood’s lawyers asked the Texas Court of Criminal Appeals, the state’s highest court, to stay the execution, but it rejected the motion, saying that the argument should have been raised sooner and that it relied on hearsay.

Mr. Hood’s lawyers then filed a motion in the county’s civil court that sought to compel Mr. O’Connell and Judge Holland to testify about their relationship.

That motion landed in the courtroom of Judge Robert T. Dry, who last week set a hearing date for two days after the scheduled execution, remarking, “In reality, you are exploring a civil lawsuit for the estate of Mr. Hood.”

Judge Dry also acknowledged that he knew Judge Holland and Mr. O’Connell well. “It is likely that every local judge knows them,” he wrote.

On Wednesday, Judge Dry suddenly recused himself, saying he had also been close friends and business partners with Judge Holland’s former husband, Earl Holland, who is now dead.

The case was then transferred to Judge Greg Brewer, who quickly ordered a hearing to be held on Monday to decide whether to require Mr. O’Connell and Judge Holland to testify.