By the time Jack Unterweger arrived at the Los Angeles Police Department, he was something of a celebrity. Back in Vienna, his prose had won him the adulation of the coffeehouse cognoscenti and a literary prize. In Los Angeles, he was the silver-haired intellectual come to research a story on prostitution in the United States.
It seemed only natural to allow a journalist of his stature to ride along with officers, bringing him to the street corners at the heart of the Los Angeles sex trade. Of his experience, he wrote: "Real life in L.A. is dominated ... by the broken dreams of thousands who come daily to the city and an equal number who leave, sometimes dead."
Within months, however, the urbane Austrian author famous for his silk suits and his car with a "JACK 1" license plate was in prison, charged with killing 11 prostitutes - including three during his stay in California.
Today, a decade later, as another man - a father of two and former Cub Scout leader in Wichita, Kan. - stands accused of 10 murders, Unterweger's tale serves a reminder that the public lives of serial killers are often intertwined with the ordinary. For generations, notorious murderers have been embraced as kindly grandfathers and celebrated as civic leaders - with one even meeting America's first lady.
Yet the charges in Wichita come at a peculiar time. Many Americans are leading insulated lives - knowing more about their computer mouse than their co-workers. Increasingly, companies, universities, and online dating services are being pressured to supplement handshakes with background checks and personal references with police records.
In this atmosphere, the news that a dog-catcher who sat on his local church council could have killed 10 people - and evaded suspicion for 31 years - has added unease to a nation unsure of its neighbors.
"These people are so monstrous, that it's more comfortable to us if they were monstrous all the time," says Gregg McCrary, author of "The Unknown Darkness: Profiling the Predators Among Us." "It's more unsettling if they turn out to be normal."
Two years before Jack the Ripper tormented East London in 1888, Robert Louis Stevenson published "The Strange Case of Dr. Jekyll and Mr. Hyde," about a compassionate doctor who transformed into a hideous criminal. Since then, a handful of cases have suggested that many serial killers essentially live the same way - compartmentalizing two different lives.
When one psychiatrist examined New Yorker Albert Fish in the 1930s, he wrote that Fish "looked like a meek and innocuous little old man.... If you wanted someone to entrust your children to, he would be the one you would choose" - this of a man who admitted to numerous murders and cannibalism. In the late 1970s, John Wayne Gacy entertained children as a clown, became a local Democratic leader in the Chicago area, and even posed for a picture with first lady Rosalynn Carter - all during the time he was murdering boys and young men, ultimately killing 33.
"They are extraordinarily ordinary," says James Alan Fox, author of "Extreme Killing." "Someone who looked like the stereotype would be easy to catch and wouldn't fool anyone."
According to Wichita police, Dennis Rader fooled his neighbors for more than three decades, living among them as an animal-control officer and as the father of an Eagle Scout. The tip that led to his arrest emerged only when the so-called "BTK killer" began communicating with authorities again after some 20 years of silence.
In the 1970s, an anonymous author sent coded letters to media outlets in Wichita claiming responsibility for six killings. The killer became known as the BTK killer for one code that stood for "bind, torture, kill."
Last year, the correspondence resumed, and reports suggest that Wichita police recently traced a computer disk sent by the BTK killer to a computer in Mr. Rader's church.
The 31-year investigation speaks to the difficulty of finding modern-day Dr. Jekylls. But there is also fresh concern among some criminologists that the growing isolation of American culture could make investigations even harder in the future.
In America's more mobile society, families are less likely to forge long-term ties with neighbors on sidewalks and streetcorners. Moreover, increasing commutes are cutting into time to socialize, and the advent of the Internet has meant that people are as likely to chat with someone across the country as across the picket fence.
"We don't know our neighbors as well as we think we do," says Robert Putnam, author of "Bowling Alone: The Collapse and Revival of American Community." "How likely am I to notice my neighbor doing something a little odd?"
Given that murder cases are typically solved by investigating the links and relationships of the victim, a more splintered society makes it harder to connect the dots. To be sure, each case is unique. Unterweger, for one, had been imprisoned for murder before. He became a cause célèbre for Austria's literary community only after he taught himself to read in prison and began writing plays. Although he was a model of prison rehabilitation when he was paroled in 1990, police linked him to the 11 murders in Europe and Los Angeles two years later.
Many cases, however, involve suspects more like Rader, whose background was so clean that he passed a Boy Scout background check. Moreover, most serial murders are random, meaning that the criminal had no prior connection to the victim - giving authorities few leads. The advent of DNA evidence has helped, but it is no replacement for shoe leather, experts say.
"We're making strangers of each other," says Steven Egger, author of "The Killers Among Us." "Consequently, people can move around in a neighborhood with a fair amount of anonymity."