RICHMOND, FEB. 19 -- Virginia Gov. L. Douglas Wilder today commuted the death sentence of convicted murderer Joseph M. Giarratano Jr., whose scheduled electrocution Friday had become a rallying point for death penalty opponents.

Wilder's conditional pardon, which Giarratano's supporters said he will accept by a 5 p.m. Wednesday deadline, reduces the sentence of the drug addict-turned-legal expert to life imprisonment with the possibility of parole 13 years from now.

The governor, who has refused three other pleas for clemency from condemned murderers during his 13 months in office, gave no reason for his decision in the commutation offer. Aides said any comment from him might prejudice a new trial that Giarratano is seeking. Wilder said earlier in the day that the decision was "complex but not difficult."

"I have thoroughly reviewed the evidence in the case," Wilder wrote. ". . . . I have been subjected to significant pleas from across the United States and other parts of the world . . . . While they have been sincere in their expressions of concern . . . the overwhelming majority acknowledge that they do not enjoy a grasp of the specific facts in the case. I, on the other hand, do, as I must."

A group that has worked with Giarratano on his appeals for clemency praised Wilder's decision, but said it did not go far enough.

"It would have been a terrible miscarriage of justice if Joe had been executed," said Mandy Bath, a spokeswoman for the Virginia Coalition on Jails and Prisons. "Nonetheless, we still feel prison is not the right place for a man who may well be innocent." Bath said the coalition will continue to press for a new trial, a request Wilder said he could not grant.

The clemency offer was angrily attacked by a relative of Giarratano's victims, 44-year-old Barbara Kline of Norfolk and her 15-year-old daughter, Michelle, who were stabbed to death and strangled in 1979.

"Governor Wilder has done a political thing -- he's trying to run for president," said Earl F. Jones of Delmar, Del., Barbara Kline's brother-in-law. "He's let a killer get away."

"Giarratano is sitting there now laughing at the system," Jones said, adding that his family plans to try to make the decision an issue in any campaign Wilder, a Democrat, mounts for national office. "I thought he was a fair man, but this is all politics. The country doesn't need a person like this."

Giarratano's attorney, Gerald T. Zerkin, said his client was still studying Wilder's commutation offer in his cell at the prison here, where Virginia's electric chair is housed, and declined to comment further.

Wilder's offer of clemency -- the first time a Virginia governor has intervened since executions resumed in Virginia in 1982 -- came after intensive lobbying by a broad coalition that included some prominent death penalty supporters. They said they were bothered by new evidence raising doubts about Giarratano's guilt.

Wilder said that Giarratano, 33, should be eligible for parole after serving 25 years, including credit for the 12 years he already has served. That would make him eligible for release in 2004.

If any part of his clemency order is challenged in court, Wilder wrote, Giarratano "is not to be released from prison, but instead his sentence will be commuted to life imprisonment without parole."

The clemency offer stopped short of what Giarratano sought.

The governor did not call for a new trial. He said that decision rests with Attorney General Mary Sue Terry, who has consistently maintained that there are no grounds for a second trial. Giarratano has offered to waive his constitutional right to protection from "double jeopardy" and said he would submit to another trial.

Wilder's claim that Giarratano would be eligible for parole if he maintains good behavior in prison is clouded by uncertainty. The governor acknowledged in the offer that Virginia law says inmates whose death sentences are commuted are not eligible for parole, but asserted that his clemency powers under the Virginia Constitution override the law.

The governor's position was supported by a prominent expert on the state constitution.

"The governor is entitled to have the full power of clemency," said University of Virginia law professor A.E. Dick Howard, who helped draft the most recent updating of the Virginia Constitution in 1971. "The governor's power is constitutionally granted . . . and it is intended to be broad."

Terry was criticized today by Harvard University law professor Laurence H. Tribe for her advice to Wilder that a new trial was not an option even if Giarratano waived his double-jeopardy protection.

In a letter to the Bath's coalition, Tribe wrote that he was "deeply offended that {Terry} should propound spurious legal arguments in an effort to persuade a governor that a perfectly lawful and sensible exercise of the pardoning power is somehow beyond his legal authority."

Bert Rohrer, a spokesman for Terry, declined to comment on Tribe's criticism. He also said it "would be inappropriate to comment" about Wilder's clemency offer before the deadline for Giarratano to sign it.

Giarratano now says he was in a drug-induced stupor at the time and has no recollection of the crime. He said he assumed he was guilty when he gave the five confessions that became the cornerstone of the prosecution's case against him.

After overcoming drug addiction in prison, he began to fight for his survival. Giarratano's attorneys argued that the confessions are contradictory and were coached by investigators.

Giarratano's attorneys say there are holes in the prosecution's case.

Forensic experts believe that Barbara Kline was stabbed by a right-handed assailant; Giarratano is left-handed. Also, a knife believed to be the murder weapon was never found, even though Giarratano said he threw the knife in the yard behind the apartment building where the slayings occurred. No blood was on his clothes at the time he turned himself in, although the stabbing scene was bloody.

While housed at Virginia's Mecklenburg Correctional Center, Giarratano pursued not just his own case in the courts, but also those of many fellow inmates. A case he filed arguing the right of death-row inmates to state-supported counsel reached the U.S. Supreme Court, which ruled against him.

It was this evolution that attracted several prominent supporters to his cause, including singer Joan Baez and actor Mike Farrell. Conservative writer James J. Kilpatrick, a death penalty supporter, wrote columns on Giarratano's behalf. Wilder received 6,000 letters and phone calls in support of Giarratano.