The Supreme Court, already having sanctioned the death penalty, turned its attention yesterday to the escalating pace of executions in the United States, and heard warnings that lower courts are "crash scheduling" death-row appeals without giving defendants a fair chance.

The justices were also told that executions are not being carried out fast enough.

Douglas M. Becker, Texas assistant attorney general, said delays have produced a backlog of 1,100 death-row inmates throughout the country. It is a "national tragedy," he said, and is undermining public confidence in the criminal justice system.

The opposing arguments, which mirrored the nationwide debate about implementation of the death penalty, were made in the most important capital punishment controversy being faced by the court.

The case is that of Thomas A. Barefoot, convicted murderer of a Texas policeman, and its resolution is expected to have a major impact on how courts handle the recurring drama of the last-minute appeal. That drama is expected to become more frequent as the pace of executions increases.

Barefoot was convicted in November, 1978, of the unprovoked killing of a police officer attempting to question him about a nightclub fire in Harker Heights, Tex. After unsuccessfully appealing his death sentence through state courts and the U.S. Supreme Court, Barefoot turned to the federal courts.

He received a full hearing before the U.S. District Court, which denied his petition and request for a stay of the execution, scheduled at midnight last Jan. 24. But it gave him permission to petition further to the U.S. 5th Circuit Court of Appeals in New Orleans.

To that point, Barefoot's treatment was relatively routine, and would have remained so had the appeals court fully considered his arguments and issued a ruling. But, with only four days remaining before his scheduled execution by lethal injection, the appeals court declined to grant a full review and issued a summary opinion saying his arguments had no merit.

The same appeals court had taken an identical course when it allowed the execution last December of Charlie Brooks, also convicted of murder in Texas. The actions produced an outcry from death-penalty opponents that courts had begun rushing the appeals process in a manner that could produce a flood of rapid executions.

The U.S. Supreme Court blocked Barefoot's execution and scheduled expedited arguments in his case, Barefoot vs. Estelle. Since then, only one execution has occurred: convicted murderer John Louis Evans III was electrocuted in Alabama last Friday.

"The pipeline is filled," Jack Greenberg of the NAACP Legal Defense and Education Fund told the justices yesterday. "Executions are occurring . . . . The federal judiciary cannot be allowed to operate on a crash schedule now," he said.

"Ordinary embezzlers and thieves" receive more thoughtful treatment from appeals courts than did Barefoot, Greenberg said. He said a less time-consuming approach might be appropriate for defendants making "successive" appeals to federal courts on the same issues.

But he proposed that first-time petitioners automatically be granted full appeals court reviews, with "four to six months" to prepare instead of "four to six weeks."

Justice John Paul Stevens asked Becker "what the great emergency" was that caused the state to rush in Barefoot's case.

Barefoot "had a number of years to prepare" and his arguments have been reviewed "in nine separate proceedings by 51 judges" over four years, Becker replied. "None of them found any merit" to Barefoot's appeal, he said.

"I think it is appropriate in these circumstances to speed the process ," Becker said.

"Nobody is sentenced to life on death row," Becker had said at the beginning of his presentation.

The court also heard arguments on the substance of Barefoot's appeal: that "hypothetical" testimony from psychiatrists concerning how dangerous a defendant might be in the future should not be allowed in death penalty cases.

In Texas, such testimony is part of the sentencing process in capital cases even though it has been condemned by the American Psychiatric Association.