The Justice Ministry said Thursday that Waltraud Wagner, 49, and Irene Leidolf, 46, would be freed by the end of August on a conditional basis because of good behavior while behind bars since 1991.
"The death angels are getting out!" the Heute newspaper headlined, underscoring widespread angst over a seven-year killing spree most Austrians would prefer to forget.
Word of their impending release comes as this tiny Alpine nation is still struggling to cope with this year's horrifying scandal, Josef Fritzl's alleged 24-year imprisonment of a daughter prosecutors say he used as a sex slave.
The twin horrors have many Austrians wondering if their justice system is harsh enough on society's most outrageous offenders.
Although both Wagner and Leidolf were convicted of murder in the 1983-89 slayings at Vienna's Lainz Hospital and sentenced to life imprisonment, in Austria that maximum penalty typically means 15 years of incarceration. Like other European nations, Austria does not have the death penalty.
Authorities declined to comment on a report in the weekly magazine News detailing how both women allegedly have been free for months to leave the prison for day trips to get their hair done or do some shopping. News said the outings were part of a prerelease program designed to prepare the pair for their new life outside prison.
Wagner, Leidolf and two accomplices were convicted of what they had characterized as mercy killings of old and chronically ill patients.
Prosecutors countered that the slayings were cold-blooded murder and said some of the victims suffered terribly. The presiding judge denounced the women's "malicious methods" - administering intravenous injections of large doses of insulin and tranquilizers, or pushing tongues aside and pouring water down the elderly patients' windpipes.
The two accomplices, Maria Gruber and Stefanija Mayer, were convicted as accessories on lesser charges of attempted murder and manslaughter. Both were released a few years ago and were issued new identities as a precaution against vigilantes, officials said Thursday.
No officials would comment on whether Wagner and Leidolf will get new identities.
The four women initially admitted to involvement in the deaths of up to 42 elderly patients at Lainz Hospital, a clinic that has since been converted to a nursing home. Officials said they later retracted most of those confessions.
Wagner and Leidolf have been confined for nearly 20 years - well over Austria's usual "life" term. But some Austrians are still troubled that the murderers are getting out of prison with decades of life still ahead of them.
"It's inhumane and immoral to execute a killer, but it's not fair to their victims' loved ones when a killer can look forward to a nice life outside prison," said Anna Rietsch, a bookkeeper shopping at Vienna's main open market.
Fritzl, a retired engineer, is expected to go on trial before the end of the year for allegedly holding his daughter Elisabeth captive in a windowless cell from the time she turned 18 until this past April and fathering seven children with her.
Investigators say DNA tests have confirmed he is the biological father of the six surviving children, who include three imprisoned along with Elisabeth. Three others were brought upstairs as infants and raised in the open, and a seventh allegedly died in infancy in the basement and was tossed into the furnace.
Prosecutor Gerhard Sedlacek says Fritzl could face a murder charge if investigators determine his actions - or inaction - resulted in that child's death. But unlike Wagner and Leidolf, who were 32 and 29 when they were imprisoned, Fritzl is 73, and may well spend the rest of his days behind bars if convicted.
It has been a long season of salacious scandal for Austria.
In August 2006, Natascha Kampusch - then 18 - escaped from the windowless cell where kidnapper Wolfgang Priklopil had confined her for 8½ years after abducting her at age 10 as she walked to school.
Priklopil then killed himself by jumping in front of a rush-hour commuter train within hours of Kampusch's escape.