Inside the Brains of Psychopaths

by RupertTaylor

In cutting-edge research neuroscientists are trying to understand the brain functions of serial killers

If the popularity of grisly crime fiction and mad-slasher movies are any indication there is a widespread public fascination with psychopaths. However, as Time Magazine noted in May 2012 “Thankfully, such offenders are far less prevalent in reality than they are in entertainment - but the disproportionate damage done by violent and even non-violent psychopaths not surprisingly attracts intense scientific interest as well.”

What Is a Psychopath?

A system of measuring psychopathy

The Hare Psychopathy Checklist (PCL) was developed in Canada by Dr. Robert Hare in the 1970s and revised in 1991 as PCL-R.

It is used by psychiatrists to assess subjects through face-to-face interviews and a review of their clinical files and court records. The clinician scores 20 characteristics:

  • glib and superficial charm;
  • grandiose (exaggeratedly high) estimation of self;
  • need for stimulation;
  • pathological lying;
  • cunning and manipulativeness;
  • lack of remorse or guilt;
  • shallow and superficial emotional responsiveness;
  • callousness and lack of empathy;
  • parasitic lifestyle;
  • poor behavioural controls;
  • sexual promiscuity;
  • early behaviour problems;
  • lack of realistic long-term goals;
  • impulsivity;
  • irresponsibility;
  • failure to accept responsibility for own actions;
  • many short-term marital relationships;
  • juvenile delinquency;
  • revocation of conditional release;
  • criminal versatility.

Studies show that about one in 100 people meet the diagnostic criteria for psychopathy. However, not all psychopaths commit murder, and not all murders are committed by psychopaths.

A Savage Crime

In 1983, 10-year-old Jeanine Nicarico was savagely beaten, raped, and murdered

Jeanine was taken from her suburban Chicago home in a crime that caused widespread fear and anger in the community.

According to Time Magazine (March 1999) “residents slept a little better after police arrested Rolando Cruz, a street tough from a nearby town.” Even though convicted and sentenced to death, Cruz was innocent of the crime and police admitted fabricating evidence against him.

It wasn’t until 2009 that the real murderer was identified, when Brian Dugan pleaded guilty to killing Jeanine Nicarico. He had already been found guilty of two other murders and had collected a string of rape convictions during his 53 years of life.

Dugan was handed the death sentence for the murder of Jeanine Nicarco. Following the sentencing, DuPage County State’s Attorney Joe Birkett described Dugan as “Amongst the worst of the worst…He chose to become who he is, a serial rapist and a murderer.”

Dr. Kent Kiehl of the University of New Mexico begs to differ with the learned counsel.

Psychopathic Behaviour not a Choice

The psychopathic brain has different wiring

Dr. Kiehl has studied hundreds of psychopaths and uses the Hare Psychopathy Checklist to assess their level of dysfunction.

One of the people he has studied is Brian Dugan (left in an early mugshot). In an interview with National Public Radio (June 2010) Dr. Kiehl notes that the Hare test results give a score of between zero and 40: “The average person in the community, a male, will score about four or five. Your average inmate will score about 22. An individual with psychopathy is typically described as 30 or above. Brian scored 38.5 basically. He was in the 99th percentile.”

He cannot feel empathy and does not experience emotions. As with most psychopaths Dugan says he feels sorry for what he’s done, but such statements of remorse are solely for the benefit of parole boards, they are not emotions that are experienced.

BBC News quotes Dr. Kiehl as saying that Dugan “struggles to try and understand why people even care about what he did. Clinically, it is fascinating.”

And, Barbara Bradley Hagerty at NPR adds, “Kiehl says the reason people like Dugan cannot access their emotions is that their physical brains are different. And he believes he has the brain scans to prove it.”

Discovery Documentary about Psychopaths

The film includes a section on Dr. Kiehl’s work

Mobile Brain-Scan Laboratory

Anti-social brain wiring

To assess the brain function of psychopaths Dr. Kiehl has acquired the latest brain imaging technology and has mounted it in a truck. This means he can take his mobile laboratory to maximum-security prisons to scan the brains of inmates with known psychopathic traits.

The BBC reports that examinations have shown Dugan’s brain has abnormalities in the para-limbic system; this is the “ ‘behaviour circuit’ of the brain, including brain regions known as the amygdala and pre-frontal cortex.”

These are areas associated with processing emotions, and earlier studies have shown that brain injuries in these regions often cause the behaviour of people to change and to become anti-social.

People such as Brian Dugan simply cannot grasp the horror and revulsion their crimes create in normal people. Dr. Kiehl says “Talking about his crimes, it’s like asking him what he had for breakfast.”

Dr. Kiehl says “I tend to see psychopaths as someone suffering from a disorder, so I wouldn’t use the word evil to describe them.”

The Mind of a Psychopath

Tommy Lynn Sells, who says he killed 70 people, describes how committing murder gave him a rush similar to a drug high

Impact of Research on Legal System

Complete failure to experience empathy

In psychopaths the failure to feel emotion is genetically determined, although there may be some environmental influences as well.


This leads some defence lawyers to argue that psychopaths should not be convicted, and possibly executed, for a condition they were born with and over which they have no control.


So, the big question is whether the current justice system can properly handle psychopaths. This brings us to the burgeoning field of neuro-law.


The MacArthur Foundation Research Network on Law and Science at Vanderbilt University says it is examining the intersection of criminal justice and neuroscience to:

  • determine “the law-relevant mental states of defendants and witnesses;”
  • assess “a defendant’s capacity for self-regulating his behaviour;" and,
  • assess “whether, and if so how, neuro-scientific evidence should be admitted and evaluated in individual cases.”

Brian Dugan has not had his date with the executioner. In March 2011, Illinois Governor Pat Quinn abolished capital punishment in his state and Dugan’s sentence was changed to life in prison.


Tommy Lynn Sells remains on death row in Livingston, Texas awaiting the setting of an execution date.


“Psychopaths vs. Sadists: Brain Science, Public Fascination.” Maia Szalavitz, Time, May 14, 2012.

“Hare Psychopathy Checklist.” Encyclopedia of Mind Disorders, undated.

“The Frame Game.” Adam Cohen, Time Magazine, March 21, 1999.

“Serial Killer Brian Dugan Gets Death Penalty.”, November 12, 2009.

“Inside A Psychopath’s Brain: The Sentencing Debate.” Barbara Bradley Hagerty, National Public Radio, June 30, 2010.

“Psychopaths: Born Evil or with a Diseased Brain?” Matthew Taylor, BBC News, November 14, 2011.

"Law and Neuroscience." Research Network on Law and Neuroscience

Updated: 12/31/2013, RupertTaylor
Thank you! Would you like to post a comment now?


frankbeswick on 01/01/2014

How right you are about some psychiatrists. I remember meeting one at a party who managed to annoy me and insult his wife publicly in the same sentence. To spare his wife I said nothing, but I was thinking, "And you are claiming to heal people!"

RupertTaylor on 01/01/2014

Sorry Frank. I misread your comment although it was clear what you wrote and required considerable effort on my part to get it wrong.

I've heard it said that some psychiatrists go into the profession in order to figure out what's wrong with them.

We had a psychiatrist neighbour once of whom that could be clearly said. My wife and I also decided he had married one of his more severely afflicted patients. Truly a very odd couple.

Sheri_Oz on 01/01/2014

Yes, I also read an article about the psychiatrist who discovered his brain scan is similar to that of a psychopath. That raises the question if the psychopath's brain scan is really unique or if someone with psychopathic tendencies can be raised to overcome them. Probably there is truth in both ideas.
Good article.

frankbeswick on 12/31/2013

The psychiatrist was not a cleric.

My experience of being in the religious life as a trainee priest [I quit after three years] was that I met no psychopaths, but I knew a few power freaks.

RupertTaylor on 12/31/2013

Yes. I can see the clergy having a few psychopaths in its ranks, but they are not alone.

A 2013 article in Forbes magazine notes that “troubling research indicates that in the ranks of senior management psychopathic behaviour may be more common than we think.”

frankbeswick on 12/31/2013

Interesting article.

There was an article in the Catholic Herald recently that told of how a psychiatrist had identified certain characteristcs in the brain scans of psychopaths, and as a control he tested all his own extended family. He found one in the family who had psychopathic characteristics. Nervously he inquired who it was and found out that it was his own scan. Yet he is well-behaved and civilised. He concluded that environmental conditions had overridden his innate tendencies .

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