A DuPage County jury heard Wednesday from the second of three defense experts who agree Brian Dugan is a psychopath with an abnormal brain.
Dr. James Cavanaugh testified the multiple murderer suffers from the significant mental and emotional disorder, but that his psychopathy has diminished over time due to aging, incarceration and self-improvement efforts.
Cavanaugh is a noted forensic psychiatrist involved in many notorious criminal trials of the last quarter century, including those of serial killer John Wayne Gacy and John Hinckley Jr., for his 1981 attempted assassination of President Ronald Reagan.
The doctor also testified in the case of Marilyn Lemak, a Naperville woman serving a life prison term for killing her three children in March 1999 in the midst of a divorce. Cavanaugh served as a prosecution expert who found all three defendants were legally sane when they committed their crimes.
Dugan's legal responsibility is not at issue since he pleaded guilty more than three months ago to the 1983 murder of Jeanine Nicarico, 10, of Naperville. Rather, the jury of seven women and five men will determine his punishment - execution or a life prison term.
The sentencing hearing, which began Oct. 6, may end late next week.
Dugan, 53, has been serving two life prison terms since 1985 for the sex slayings of nurse Donna Schnorr, 27, of Geneva, and 7-year-old Missy Ackerman of Somonauk.
His defense team is expected to rest today with its star witness - neuroscientist Kent A. Kiehl. Kiehl will tell jurors about his vanguard research of psychopaths, including Dugan, who the forensic psychologist found, through the use of brain scanning technology, share a defect or inactivity in an area of their brains that processes emotion, inhibition, judgment and self-control.
That point is not in dispute. Lawyers are presenting dueling experts, though, regarding whether the structural brain defect rendered Dugan defenseless to control his violence.
As for Cavanaugh, he declined to speculate whether there's a causal connection.
"It doesn't suggest an explanation for what he did," said Cavanaugh, director of the Isaac Ray Center in Chicago. "It doesn't suggest diminished responsibility. It is what it is. His brain is abnormal. That is something the jury may want to consider."
He said Dugan is the product of a dysfunctional family and suffered emotional, physical and sexual abuse. Dugan also has a history of head injuries and exhibited, as early as 8, key traits found in psychopaths, including bed-wetting, animal cruelty and igniting fires.
Prosecutors argue Dugan is a master manipulator who is continuing his long pattern of conning mental health experts to get what he wants which, in this case, is his own self preservation. They listed examples in which he made inconsistent statements to various experts. Dugan has a high IQ and is known to read psychiatry books. Dugan told the experts he has suicidal thoughts to try to atone for his crimes, but he's never acted on them.
Cavanaugh disagrees that Dugan is pulling another con.
"You can't read a couple of books and figure out how to manipulate neuroscientists, psychiatrists and psychologists," he said. "A more reasonable explanation is he's trying to understand why he did what he did. He knows he is ... messed up and he's interested at some level to learn more about that."
Cavanaugh continued: "This (brain scan imaging in psychopathy) is not junk science. It's not a situation where some crackpots got together and cooked up some theory for court without scientific evidence."
Dugan is not expected to testify, but jurors heard plenty of his words through recorded interviews with law enforcement and mental health experts, from 1985 to two months ago. In a two-hour Sept. 5 videotaped interview with Kiehl, a relaxed Dugan described himself back then as a "nymphomaniac" who, while high on drugs and alcohol, impulsively attacked victims - most of whom he saw as objects and not real human beings.
Dugan said he has tried to better himself in prison through participating in satellite college classes, physical fitness, avoiding trouble and reading psychology books. Dugan said he had an epiphany years ago and chooses to no longer deceive or harm. He spoke of remorse, but Dugan also admitted he still fantasizes about young girls.