Crime + investigation

A Forensic Psychologist on the Case That Gave Him Nightmares

Dr. Richard Lettieri, a forensic neuropsychologist and psychoanalyst who's assessed hundreds of murderers throughout his career, talks to us about his most memorable cases and his book, 'Decoding Madness.'

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Published: July 22, 2021Last Updated: September 15, 2025

A man who kills his wife and then goes out for a night on the town with his mistress. Another who stabs his mother to death, then phones his sibling to confess.

What were these people thinking?

That's the kind of question that has guided the career of Dr. Richard Lettieri, a forensic neuropsychologist and psychoanalyst who's assessed hundreds of murderers in a career spanning nearly 30 years. His new book, "Decoding Madness: A Forensic Psychologist Explores the Criminal Mind," explores some of his most noteworthy cases.

We caught up with Dr. Lettieri to discuss some of his most memorable cases.

I'd like to start by discussing the case of Tina: a woman who repeatedly stabbed her partner, Bentley, and also fatally stabbed his 10-year-old daughter, Lisa. You said in the book that this case gave you nightmares. Why did this case rattle you so much?

Having to view all the crime scene, and the abject horror of it, and the juxtaposition between that and her blasé attitude [about her crimes].

She wasn't psychotic, she wasn't schizophrenic, she wasn't delusional, she didn't hear voices. But there was a detachment that I found disturbing. Like when she told me [in the middle of an interview] that she wanted to have her driver's license renewed.

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She had an ability to split: [She believed] people were all good or bad. And if someone was against her, she'd devalue them. So there was no anguish. Maybe I was [so disturbed] because she was so cut off.

I don't find myself [getting so disturbed] with someone who is truly mentally ill: Even if they're threatening me, I feel a compassion about it. But with this woman it was: 'Wow.'

I imagine a lot of the sociopathic killers you evaluate lie to you, because your report can have consequences on their sentences. Do you ever feel like they're trying to manipulate you?

It's unlike a clinical situation. With patients I don't interview their families. I don't get their records. With criminal cases I get all of that.

But it happens. In the chapter I wrote, “My Brain Made Me Do It” about Peter, he was clearly a psychopath. He was in prison already serving a very long term, and then he shanked somebody.

He came down [to meet with me] with Erving Goffman's book, Asylums, about how institutionalization affects people. And he was telling me he'd been institutionalized his entire life, that ' I can't help but be the way I am.' And he was very manipulative —and very demanding.

There was no doubt this guy was antisocial, but more importantly: psychopathic. He was very cruel, and he showed very little remorse.

But you talk long enough with someone, [they'll have] a human desire to speak out and express themselves. So information starts to come out. I start to get a picture of things. And I do psychological testing and cognitive testing.

That's what I did today with a guy who killed his girlfriend.

Who was that? Can you speak about today's case?

This man: He's got a history of learning disabilities. [He's] a slow learner. And then he had a major car accident 15 years ago where he was in a coma for two weeks. He's probably got frontal lobe problems, based on the history I've seen.

He impulsively strangled his girlfriend to death and he then reported it afterwards. It won't excuse [his behavior], but it will probably be mitigating if the neuropsychological testing shows he has frontal lobe problems. It's probably orbital frontal. And someone like that probably has less control, less executive function.

Another case you document is that of Michael: a man who murdered his own mother. Ultimately, you believed Michael's version of events, and as a result, he successfully pleaded criminal insanity. Why'd you believe him and not some of the others?

There are multiple pathways to violence. And one is a major mental illness like schizophrenia. Michael had schizophrenia and paranoid type, which is the most dangerous because when you're affected by hallucinations and delusions, you can't 'reality test.'

He had this delusion about the sun burning up—that the sun was coming down from the sky to burn him up. It was very bizarre. Sometimes [delusions] make more sense, like they think the CIA is coming after [them] … but this was that the sun [was] descending down on him, and he had to kill his mother because she was the one doing this.

It was a clear delusion, but after he did it he realized there was no change in the sun. And so he called one of his siblings, and the police came and arrested him. But with a case like that, the thing that has to be ruled out is, 'Is he faking it?' Because that's something that always has to be addressed in forensic cases.

But the delusions Michael had went back a while. We did psychological testing for validity, for honesty.

There was a cohesiveness to the story—not just what he tells me, but all the collateral information, the reports, the interviews. And examining the issue with him over and over again. With him it was clear. That was one of the easier ones to believe. He was very credible. And a very sick guy.

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Adam Janos

Adam Janos is a New York City-based writer and reporter. In addition to his work with A&E Crime + Investigation, he is also the lead writer for Hack New York. He holds an MFA in Creative Writing from Rutgers University and is currently developing a one-man show.

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Citation Information

Article title
A Forensic Psychologist on the Case That Gave Him Nightmares
Website Name
A&E
Date Accessed
September 26, 2025
Publisher
A&E Television Networks
Last Updated
September 15, 2025
Original Published Date
July 22, 2021
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