The Austrian man who allegedly imprisoned his daughter and fathered seven children with her first planned to build his secret cell as early as 1978, when his daughter was 12, authorities said today.
Investigators said a total of eight doors fitted with sophisticated locks and electronics secured the underground warren of windowless rooms where they say Josef Fritzl held his daughter captive for 24 years.
"This was not built from one day to the next," said police Colonel Franz Polzer, who is overseeing the investigation into a case that has stunned Austria and the world.
Polzer said an investigation showed that the apartment complex owned by Fritzl originally was built in 1890, and that he applied for permits to expand it in 1978. He said police believe the plans for that expansion included the secret rooms because adding them later would have been far more difficult and expensive.
Prosecutors told reporters in Amstetten, Fritzl's hometown about 75 miles west of Vienna, that they will have their first meeting with the 73-year-old suspect on Wednesday or Thursday.
Officials said Fritzl's wife, the daughter he allegedly imprisoned and raped, and the children born of the illicit relationship are learning how to live together as they get psychiatric care and counselling.
Fritzl's lawyer, meanwhile, indicated he is preparing an insanity defence.
In an interview broadcast late yesterday, attorney Rudolf Mayer said he believes Fritzl has a serious mental disorder and that anyone with that kind of psychological illness "didn't choose" to do what police allege he did.
Mr Mayer said experts will have to determine Fritzl's mental state and decide whether the suspect can be considered certifiably insane. If that is the case, and Fritzl is convicted, he would be confined to a psychiatric institution rather than a prison, he said.
Investigators have said Fritzl confessed last week that he held his daughter captive in a windowless cell, fathered her seven children, and tossed the body of one who died in infancy into a furnace.
"I believe that the trigger was a mental disorder, because I can't imagine that someone has sex with his own daughter without having a mental disorder," Mr Mayer said.
Fritzl has not yet been charged, but remains in pre-trial detention. Police reiterated they have no evidence that the retired electrician had an accomplice.
Investigators have said they believe Fritzl concealed his crimes from his wife, Rosemarie, who's sister said Rosemarie believed her husband's cover story that Elisabeth had run away from home to join a cult.
"We were all taken in by him," the sister, who gave her name only as Christine R, said. "Every person that looked in his eyes was fooled by him."
Christine R described Fritzl as a "tyrant" who instilled a culture of fear at home, which may have explained why his wife and other children apparently never dared venture into the cellar — which Fritzl warned was strictly off-limits.
She also said her imprisoned niece — now 42 — ran away from home as a 17-year-old, about six months before police say she was locked into the secret basement rooms. The previous attempt to flee may have made her father's story that the girl joined a cult more believable.
She also said Fritzl was jailed for "a year and half" for an alleged 1967 rape conviction, but said she could not offer details.
On Saturday, the
Oberoesterreichische Nachrichtendaily printed an excerpt of what it said was a 1967 court record found in the state archives in Linz, in which a Josef F was accused of breaking into the apartment of a 24-year-old nurse and raping her.
Police have declined to comment, saying records that old offences would have been erased under Austria's statutes of limitation. But authorities are awaiting old court records that the media say document the case.
Reuters