Disturbed people

(CNN) -- Police, medical professionals and those who know Josef Fritzl are struggling to piece together how he led a double life for more than two decades in a small Austrian town.

Fritzl, 73, admitted imprisoning his daughter in the cellar of this building for more than two decades. Those who knew Fritzl describe him in such contrasting terms -- friendly, reclusive, arrogant, a kindly grandfather -- that it seems no one really knew him at all.

At his home on Ybbsstrasse in the quiet town of Amstetten, east of Vienna, the 73-year-old retired electrician lived with his wife, Rosemarie, and the three children he has admitted to fathering with his daughter.

In addition to those three children, Fritzl fathered four other children with the now 42-year-old daughter daughter he kept imprisoned in the cellar, police said. The children were products of years of sexual assault Fritzl inflicted on her, police said. Two boys and a teenage girl were locked up with their mother in a basement dungeon. A seventh child he fathered with his daughter died, and Fritzl burned the infant's body, police said.

The three children who were locked up had not ever seen the light of day, investigators said.
Fritzl had been lying to his wife for years, telling her his daughter had dropped off the three children at the house because she could not take care of them, police said. In reality, Fritzl had forced his imprisoned daughter to write letters that made it seem that way. Police say Fritzl's wife was unaware of the other children in the cellar.

It was a deception he maintained from 1984 until just days ago.
Rosemarie Fritzl was unaware of her husband's crimes, police spokesman Franz Polzer said.
"Let me also add that we know the suspect not only possessed an increased sexual potency, he's also very dynamic, imperious and quite authoritarian in his conduct and relationship to his existing family," Polzer said Monday.

Polzer added that Fritzl made clear to his wife and the children living with them that the basement area was out of bounds. He bought food for his captives and took it to them at night.
Medical professionals have also offered their interpretations of Fritzl.

"What is chilling about this case is the cold, sociopathic detachment that Josef F[ritzl] went through year after year, decades even, to hide his crimes," said clinical psychologist Dr. Kristina Downing-Orr. "It was as if there was no remorse, no empathy for his daughter, for his grandchildren, for his wife. That's what's chilling."

She said Fritzl, who his daughter has said abused her beginning at the age of 11, possibly didn't want the relationship to end when she turned 18. So he imprisoned her.

"It's that chilling sociopathic methodology, that kind of logic, that I find particularly chilling," she continued. "But fortunately, it's very rare; we rarely see that kind of behavior."