CHICAGO (WLS) -- What kind of person is a serial killer?
According to some criminal psychiatrists, it's not surprising that Darren Vann has led police to the locations of several of his suspected victims. Psychological profiles of serial killers suggest these murders are significant events in their lives, and the killers tend to have vivid memories of them. Experts say Vann's profile fits into the pattern of many serial killers.
As police search for more bodies in Gary, possible victims of alleged serial killer Darren Vann, analysts are trying to learn more about him. While police say he has confessed to killing seven women, including 19-year-old Afrikka Hardy, investigators say they suspect he may be responsible for many more.
Experts who have studied serial killers say that is very possible. Dr. Helen Morrison is the author of a best-selling book based on her research called, "My Life Among the Serial Killers."
"They can very much mimic a human being, but they have no depth to them, they're completely hollow inside," Morrison said.
Morrison says she believes many serial killers blend into society, calling no attention to themselves. Vann, however, had several run-ins with Gary police in recent years, all related to alleged violence against women. He was also convicted of sexual assault in Austi, Texas seven years ago.
Experts say an element of sexual deviance is common among serial killers.
"For many serial killers there is a conflation of sexual gratification with the desire to perpetrate violence in the most heinous way," said Dr. Arthur Luyrigio, professor of criminal justice and psychology at Loyola University.
Rush University Medical Center's psychiatrist Carl Wahlstrom spent many hours interviewing and studying serial killer Jeffrey Dahmer. He believes there are some similarities between Dahmer and Vann, including the way both apparently confessed to numerous other murders after they were caught.
"There is clearly gratification of some kind involved. It may be considerably deviant," Wahlstrom said.