An archaic doctrine honored by state and federal courts for 110 years could send James “Whitey” Bulger to the grave free of any murder convictions — in the eyes of the law — if the 84-year-old serial killer should die behind bars while his appeal is pending, legal experts said.

“In the eyes of the law, he would be better off dead. For the victims, this would be one more galling twist of the knife,” Suffolk University law professor Rosanna Cavallaro said yesterday of the “abatement ab initio (from the beginning)” rule — by which appellate justices order trial courts to expunge both convictions and indictments if they aren’t upheld before the defendant dies.

Martin W. Healy, chief legal counsel for the Massachusetts Bar Association, said Bulger’s death could be “a game-changer.”

“This is not purely ceremonial, and its applicability is very real,” Healy said. “The appeal doesn’t just disappear and the case isn’t merely dismissed, but everything associated with the case is extinguished, leaving the defendant as if he had never been indicted or convicted.”

Cavallaro said it could also have ramifications in terms of whether the ?$19.5 million Bulger has been ordered to pay his victims in restitution would stand.

“In some jurisdictions, those things also fall apart,” Cavallaro said, “because they’re contingent on (the defendant) being convicted.”

Other high-profile Bay State villains whose deaths amid appeals wiped their legal slates clean of guilty verdicts include defrocked pedophile priest John Geoghan, who was murdered in his prison cell in 2003, and John Salvi, who apparently committed suicide behind bars in 1996 two years after he was convicted of killing two abortion clinic workers in Brookline.

Assistant U.S. Attorney Brian Kelly, who devoted 20 years to bringing Bulger to justice, bristled when asked about abatement last week, saying, “The trial happened.”

Bulger defense attorney Hank Brennan, who plans to file Bulger’s notice of appeal this week, said he hasn’t broached the abatement subject with his client.

“It’s not even a consideration in my mind,” Brennan said. “We’re going to appeal and I expect to win.”

Brennan also said Bulger will not fight the restitution order while his appeal is pending.

“We wouldn’t, at this point as a strategic tool, try and hold money hostage,” Brennan said. “All the money should be given to the families.”