How could any parent kill his own children?
That's been a typical reaction to the news that Aaron Schaffhausen was accused of slashing the throats of his three young daughters last week in River Falls, Wis.
But the phenomenon, called filicide, is more common than most people might want to believe, and not all parents who do it are mentally unhinged, according to one of the country's foremost experts.
"The general lay-public response is they must be crazy, but that's not always the case," said Dr. Phillip Resnick, a professor of psychiatry at Case Western Reserve University in Cleveland. Only some are psychotic, he said, meaning they have no command of what is real.
Resnick, who has for 40 years evaluated parents accused of killing their kids, conducted a seminal study on filicide in which he identified five types of the crime.
One type -- revenge against a spouse -- may best fit the scenario authorities laid out in the charges against Schaffhausen, 34, who was divorced from the girls' mother in January.
High-profile cases
But all the types are represented in high-profile cases from across the country and the Twin Cities in the past decade or so, including the 1998 stranglings of six children in St. Paul by their mother, and the laundry-tub drowning of an Eden Prairie infant by his father in 2010.