A three-judge federal appeals court panel yesterday unanimously upheld the federal death penalty law, rejecting a lower court's contention that recent DNA exonerations of death-row inmates have proved that capital punishment is inconsistent with the constitutional guarantee of due process of law.

Last July, a U.S. district judge in Manhattan, Jed S. Rakoff, ruled that federal prosecutors could not seek the death penalty against two heroin dealers accused of murdering a government informant because the possibility of executing the innocent made capital punishment "tantamount to foreseeable state-sponsored murder."

But the Bush administration appealed, and yesterday the New York-based U.S. Court of Appeals for the 2nd Circuit overruled Rakoff, reasoning that the Constitution guarantees the accused only the fairest and most complete criminal process possible -- not an infallible one.

"Binding precedents of the Supreme Court prevent us from finding capital punishment unconstitutional based solely on a statistical or theoretical possibility that a defendant might be innocent," Judge Jose A. Cabranes, an appointee of President Bill Clinton, wrote in the opinion for the court.

The other two members of the panel were Senior Judges Ralph K. Winter Jr., an appointee of President Ronald Reagan, and Joseph M. McLaughlin, an appointee of President George H.W. Bush.

Though Rakoff's decision affected only the case before him, it was symbolically potent, hailed by death penalty opponents as further evidence that their criticisms of capital punishment were beginning to affect the courts.

But the 2nd Circuit's decision to strike it down was not necessarily a surprise.

Rakoff had alluded in his opinion to the fact that his views of the matter were legally debatable.

"The Justice Department is pleased with the Second Circuit's definitive acknowledgement that the District Court was not authorized to overturn the Supreme Court's well-established law in this area," said department spokeswoman Barbara Comstock in a statement.

"Rakoff's decision was an alarm bell. He was trying to find a legal basis on which to hang his firm belief that there was too much risk to let this go forward," said Richard Dieter, executive director of the Death Penalty Information Center, a Washington-based nonprofit group that opposes the death penalty.

"But it would be really groundbreaking for the 2nd Circuit to have agreed with that and set a new precedent all on their own."

Samuel R. Gross, a professor of law at the University of Michigan who argued the case for the two murder defendants, Alan Quinones and Diego B. Rodriguez, in the 2nd Circuit, said no decision had been made on whether to appeal to the Supreme Court.

But he added: "The 2nd Circuit said it's up to the Supreme Court. Someday it will be, and we hope that when it is, the Supreme Court takes up the challenge."

Cabranes's opinion noted that the Fifth Amendment, which sets forth the guarantee that no one can be punished without due process of law, includes three references to capital punishment, clearly indicating that the Founders "contemplate[d] the existence of a death penalty for certain crimes."

"There is no fundamental right to a continued opportunity for exoneration throughout the course of one's natural life," Cabranes wrote.

A separate case on the federal death penalty is working its way through the 2nd Circuit.

In September, U.S. District Judge William K. Sessions of Vermont ruled that the federal death penalty law is unconstitutional because hearsay and other evidence that cannot be used at the guilt-innocence phase of a trial can be used in the sentencing phase.

"Capital punishment is under siege," Sessions wrote.

The Bush administration appealed that ruling.