NEW YORK (AP) – A federal appeals court on Tuesday blocked the scheduled execution of serial killer Michael Ross, ruling that a judge must first decide if an outside party has the right to interfere with Ross’ request to be put to death.

A three-judge panel of the 2nd U.S. Circuit Court of Appeals ruled less than an hour after hearing arguments, upholding a stay of execution issued a day earlier by U.S. District Judge Robert Chatigny in Hartford, Conn.

New London, Conn., State’s Attorney Kevin Kane said he would file an immediate appeal to the U.S. Supreme Court.

The appeals court said Chatigny can hear evidence about Ross’ mental competency to forgo appeals of his death sentence as a way to determine whether Connecticut’s public defenders can intervene in the case and file motions on Ross’s behalf. Chatigny allowed the public defenders to intervene Monday, but the appeals court said he should not have done so without first holding the competency hearing.

The 2nd Circuit urged Chatigny to act expeditiously.

Chatigny issued the stay after hearing testimony on Monday from a psychiatrist who testified that Ross’ lengthy seclusion on death row may have made him incompetent to decide to end appeals of his death sentence.

“We do not have a basis to adequately review, and to disagree with, the district court’s conclusion that there was …. meaningful evidence … that Ross was suffering from a mental disease, disorder or defect that substantially affected his capacity to make an intelligent decision,” the judges said in their five-page decision.

Hartford attorney Hubert Santos, who argued on behalf of the public defenders, was happy with the ruling. “Right result and great result,” he said.

Ross’ attorney, T.R. Paulding, said that he expected the ruling after hearing the types of questions the judicial panel was asking. He said he would talk to Ross on Tuesday evening to discuss the developments.

“I don’t think that it changes the playing field,” Paulding said.

Ross, 45, has admitted killing eight young women and girls and raping most of them in the early 1980s. He had been scheduled to be executed at 2:01 a.m. Wednesday. A judge had set the execution date after Ross fired his public defenders last year and told a judge he wished to expedite his sentence of death by lethal injection.

If the stay of execution is lifted, Connecticut officials said Ross would be put to death at 2:01 a.m. Friday. Correction officials had delayed the execution date to Thursday morning after Chatigny issued the stay, and they decided Tuesday to postpone it again to Friday.

In hearing the appeal by Connecticut state’s attorneys, Judge Robert Katzmann said the question was not whether there was adequate evidence to prove Ross was incompetent to waive his rights but whether as “somebody is about to be executed, what is the harm in having a hearing that ensures that all of the evidence that is meaningful is heard and put to the test?”

Harry Weller, a supervisory assistant state’s attorney in Connecticut, said such a hearing was not necessary because the psychiatrist who testified Monday was someone who has never spoken to Ross and who offered incorrect information or provided evidence that had been thoroughly reviewed already by the courts.

Weller said that Dr. Stuart Grassian, a former professor at Harvard University and an expert on the effects of incarceration on prisoners, “should never have testified yesterday.”

Weller said Ross has a “constitutional right to make this choice” to die, and said a third party was trying to impose its will on Ross.

Santos countered that “all Judge Chatigny wants is time.” He said the case had been “rushing through the courts the last several months.”

At one point, Judge Robert Sack suggested that if Ross wanted to die, “the legal system ought to let him make that decision.”

Santos said the reason Ross wants to die is because he cannot take his prison condition.

He said evidence of that includes 10 witnesses and Ross’ own writings in which he describes prison conditions as so unbearable that it would be better to die. Ross has attempted suicide while in prison.

Weller, though, said that the conditions have not been intolerable and that Ross has had frequent visitors and almost daily chess games.

The decision from the federal appeals court came the same day the Connecticut Supreme Court rejected another attempt by the public defenders and Ross’ father, Dan Ross, to intervene and file post-conviction motions on Ross’ behalf.

The high court ruled that lawyers had failed to prove that Michael Ross was incompetent to make his own decisions. A similar state Supreme Court decision earlier this month, denying public defenders the right to participate in a competency hearing, prompted the appeal to Judge Chatigny.

“It’s pretty clear that if there is any relief that is going to be obtained, it will be in the federal courts,” said Jon Schoenhorn, Dan Ross’ attorney.