The federal appellate court in Manhattan heard its first death-penalty appeal in more than 40 years yesterday. The three-judge panel sharply questioned the government about its strategy during the trial of Donald Fell, who was sentenced to death in Vermont in 2002.

Fell, 27, confessed to killing his mother and her boyfriend with an accomplice on November 26, 2000, and the next morning, kidnapping a 53-year-old grandmother, Teresa King, in Vermont, and murdering her across the state line in upstate New York.

That death-penalty sentence was the first to come out of Vermont since 1957, but it was later commuted.

A defense attorney for the condemned man asked the judges to overturn the death sentence on the grounds that the jury should not have been allowed to hear testimony about Fell’s interest in Satanism as a youth.

At the trial, the jury had also learned that Fell had worn a T-shirt carrying the logo and name of a heavy-metal band, Slayer, at the time that he committed the murder and for the next three days until he was tracked down in Arkansas.

During the two-hour oral arguments, the defense attorney, John Bloom, told the judges that these details were irrelevant to the murders and that their introduction as evidence prejudiced the jury against the defendant.

At least one of the justices, Barrington Parker, appeared to agree.

When a federal prosecutor, William Darrow, began describing the shirt as depicting a demon and a pentagram, the judge cut him off.

“Tens of thousands of teenagers wear the shirts with this picture on them,”

Judge Parker said. “It’s a popular heavy-metal band.”

The panel also heard arguments about whether the trial judge had been wrong to dismiss prospective jurors who wavered when asked whether they were capable of handing down a death sentence.

In addition to Judge Parker, the other two judges on the panel were John Walker and José Cabranes.

Fell awaits the panel’s decision from death row in Terre Haute, Ind.