RENEE MONTAGNE, host:
Let's get back, now, to a subject we're considering this week: the criminal brain. This morning, we're going to hear how neuroscience has entered the courtroom as neuro-law. And some scientists and legal philosophers say the law should give psychopaths a break because their brains may function differently from most people's.
NPR's Barbara Bradley Hagerty explores now the brain of a serial killer.
BARBARA BRADLEY HAGERTY: Kent Kiehl has studied hundreds of psychopaths. Kiehl is one of the world's leading investigators of psychopathy, and a professor at the University of New Mexico. He uses a scale called the Hare Psychopathy Checklist, to measure traits such as the inability to feel empathy or remorse, pathological lying, or impulsivity.
Professor KENT KIEHL (University of New Mexico): The scores range from zero to 40. The average person in the community, a male, will score about four or five. Your average inmate might score about 22. Brian scored, like, 38 and a half, basically. He was in the 99th percentile.
BRADLEY HAGERTY: Brian is Brian Dugan, a man who is serving two life sentences for murder in Chicago. Last July, Dugan pleaded guilty to raping and murdering 10-year-old Jeanine Nicarico in 1983, and he was put on trial to determine whether he should be executed. Kiehl was hired by the defense as an expert witness.
In a videotaped interview with Kiehl, Dugan describes how he only meant to rob the Nicaricos' home but then he saw the little girl inside.
Mr. BRIAN DUGAN: She came to the door and I clicked.
Prof. KIEHL: Okay.
Mr. DUGAN: I turned into Mr. Hyde from Dr. Jekyll. I couldn't stop.
BRADLEY HAGERTY: Notice the flatness of Dugan's voice. That's typical of a psychopath. And note how he describes his emotions.
Mr. DUGAN: And I have empathy, too, but it's like it just stops. I mean, I start to feel, but it just, something just blocks it.
BRADLEY HAGERTY: Kent Kiehl says he's heard that before. All psychopaths claim they feel terrible about their crimes.
Prof. KIEHL: But then you ask them, what does that mean, you feel really bad? And Brian will look at you and go, what do you mean, what does it mean? You know, they look at you like, can you give me some help? You know, hint? Can I call a friend? You know, they have no way of really getting at that at all.
BRADLEY HAGERTY: And, Kiehl says, the reason they can't get to their emotions is because their physical brains are different.
(Soundbite of gate opening)
BRADLEY HAGERTY: The gate at the Juvenile Detention Center in Albuquerque, New Mexico swings open and a huge trailer drives through. This is Kiehl's $2 million mobile MRI that he takes to maximum-security prisons. He's scanned the brains of more than 1,100 inmates, about 20 percent of whom are psychopaths.
For ethical reasons, Kiehl can't let me watch an inmate in the MRI, so he asks his researchers to demonstrate.
Prof. KIEHL: All right, Kev. You see the word ready on the screen?
Mr. KEVIN BACHE (Researcher): I do.
Prof. KIEHL: All right. For this first task, you're going to see pictures of people and events presented one at a time.
BRADLEY HAGERTY: In this test, the subject sees three types of pictures. One has no emotional or moral content. For example, students standing around a Bunsen burner. Another type is emotional but morally ambiguous: a car on fire but you don't know why. And the third depicts a moral violation.
Prof. KIEHL: There's a picture of someone about to - looks like it might shoot a child. So that might be rated as rather high moral content.
BRADLEY HAGERTY: And the subject does rate it as morally objectionable.
Kiehl says most psychopaths say that pictures like this are a moral violation, but there is a key difference. When a normal person sees this photo, the limbic system lights up. Kiehl calls that that emotional circuit. It involves the orbital cortex above the eyes and the amygdala, deep inside the brain. But when Brian Dugan and other psychopaths see the same photo, Kiehl says, the emotional circuit does not engage in the same way.
Prof. KIEHL: We have a lot of data that shows that psychopaths do tend to process this information differently. And Brian looked like he was processing it like the other individuals we've studied with psychopathy.
BRADLEY HAGERTY: Kiehl says the emotional circuit may be what stops us from breaking into that house or killing that girl. But in psychopaths like Dugan, the brakes don't work. Kiehl says psychopaths are a little like people with a very low IQ who are not fully responsible for their actions. The courts treat people with low IQ differently. For example, they can't get the death penalty.
Prof. KIEHL: What if I told you that a psychopath has an emotional IQ that's like a five-year-old? Well, if that was the case, then we'd make the same argument for individuals with low emotional IQ - that maybe they're not as deserving of punishment or not as deserving of culpability, etc.
BRADLEY HAGERTY: It's a controversial argument, but a number of prominent scientists and legal scholars at places like Harvard and Princeton agree. And that's exactly what Brian Dugan's lawyers argued at trial last November. Attorney Steven Greenberg said that Dugan was not criminally insane. He knew right from wrong, but he was incapable of making the right choices.
Mr. STEVEN GREENBERG (Attorney): Someone shouldn't be executed for a condition that they were born with, because it's not their fault. The crime is their fault, and he wasn't saying it wasn't his fault, and he wasn't saying, give him a free pass; but he was saying, don't kill me because it's not my fault that I was born this way.
BRADLEY HAGERTY: This argument troubles Steven Erickson, a forensic psychologist and legal scholar at Widener University. He notes that alcoholics have brain abnormalities. Do we give them a pass if they kill someone while driving drunk?
Dr. STEVEN ERICKSON (Forensic Psychologist, Legal Scholar, Widener University School of Law): What about folks who suffer from depression? They have brain abnormalities too. Should they be entitled to excuse under the law? I think the key idea here is that the law is not interested in brain abnormalities. The law is interested in whether or not someone, at the time that the criminal act occurred, understood the difference between right and wrong.
BRADLEY HAGERTY: At trial, Jonathan Brodie, a psychiatrist at NYU Medical School who was the prosecution's expert witness, went further. Even if Dugan's brain is abnormal, he testified, the brain does not dictate behavior.
Dr. JONATHAN BRODIE (Psychiatrist, NYU Medical School): There may be many, many people who also have psychopathic tendencies and have similar scans, who don't do antisocial behavior.
BRADLEY HAGERTY: Who don't rape and kill.
Dr. BRODIE: Who don't rape and kill.
BRADLEY HAGERTY: And, he told the jury, Dugan's brain scan in 2009 says nothing about what his brain was like when he killed Jeanine Nicarico.
Dr. BRODIE: I don't know, with Brian Dugan, what was going on in his brain. And I certainly don't know, from a brain scan that was taken 24 years later, what was going on then.
BRADLEY HAGERTY: The jury seemed to zero in on the science, asking to reread all the neurological testimony during 10 hours of deliberation. But...
(Soundbite of newscast)
Unidentified Woman (Newscaster): Breaking news now: Jurors have decided the fate of convicted murderer Brian Dugan. He has been sentenced to death.
BRADLEY HAGERTY: Ultimately, jurors said, the horrific nature of the murder earned Dugan the death penalty. Dugan is appealing the sentence.
In the meantime, this case signals the beginning of a revolution in the courtroom, says Kent Kiehl. Just like DNA, he believes that brain scans will eventually be standard fare. And that, he and others say, could upend our notions of culpability, crime and punishment.
Prof. KIEHL: Neuroscience and neuroimaging is going to change the whole philosophy about how we punish and how we decide who to incapacitate, and how we decide how to deal with people.
BRADLEY HAGERTY: And neuroscience may have already played a pivotal role in a Tennessee murder case. Tomorrow, the warrior gene goes on trial.
Barbara Bradley Hagerty, NPR News.
MONTAGNE: And you can hear the first story in our series on the criminal brain at our website, NPR.org.