Hello, friends, welcome back to the show.
My guest today is Dr.
Marissa Harrison. She's a psychologist, professor, researcher, and an author.
All the most infamous serial killers are men, but one in six serial killers are women, a group who have totally slipped under the radar.
So who are these women?
What are their motives?
And why haven't we heard of them?
Expect to learn why female serial killers are so neglected in research.
What the average demographic of a female serial killer is?
Who are the most likely victims of a female serial killer?
Why they kill? The methods they use?
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But now, ladies and gentlemen, please welcome Dr.
Marissa Harrison. Why is it particularly interesting to study female serial killers?
I think it's interesting because there seems to be this preconceived notions that all serial killers operate the same way, and when we think of a serial killer, we think of in the United States, Ted Bundy or Ed Kemper, we think about monstrous males who commit sex crimes, and female serial killers might be
monstrous for some people's definitions, but they tend to be more low -key, they tend to poison people, they tend to kill for money and power versus male serial killers tend to kill for sex.
So there are profound sex differences.
So I think it's interesting to bring that to public attention.
Right, so you're like a promoter of females, not a promoter, not quite saying that they're good, but just maybe a little bit more attention should be paid.
Why have they been so neglected beyond the fact that maybe the way that they kill is less extravagant?
I agree with you. First, let me say, when I was writing the book Just as Deadly, The Psychology of Female Serial Killers, I was thinking to myself, is this a feminist book?
Because I'm saying women can do that too.
And it's a really horrible argument of equality, but the thing is they can.
So you had asked, why might people pay attention to males more so than females?
And I think there's this age -old notion, and I'm certainly not the first person to say this, but I think there's this age -old notion that women can't be damaging, women can't be dangerous, women are nurturing and caregivers.
So if I said to you, Grandma, you might think of, well, let me ask you this, Chris, what do you think of when you think of Grandma?
Soft, gentle, caring, mothering, sleepy.
Exactly. What if I told you about the giggling granny Nanny Doss who killed her mother, likely her sister, I think three husbands, some of her grandchildren.
And when they interviewed about it, she laughed.
So that doesn't fit my schema of Grandma.
And she looked like a grandma, right?
So what we might think of Grandma would look like maybe, I don't want to get in trouble for saying this, but, you know, maybe like an old -school 1950s house coat in the kitchen, cooking bread, all that kind of stuff.
And you wouldn't suspect that she would do these things.
And I think that's why we are maybe not so quick to catch female serial killers.
And we're really not so quick to think, yeah, she did that.
And I have some stories for you if you would like about that type of thing.
I would like, yes. Oh my.
So I get some really interesting, I can't say fan mail, but attention from Lucy Letby committed her crimes in the United Kingdom in Chester, right?
Chester, England, and Cheshire, United Kingdom.
Lucy Letby was a neonatal nurse.
She was a very skilled nurse.
And she was convicted last year, 2023, of killing, I think it was seven infants.
And I was asked to talk about that on some podcasts and some other interviews in the United Kingdom.
Well, I got my share of colorful emails.
I'm wrong. I'm, how could I ever be so stupid?
They made fun of my American accent.
Thank you. They said, I must be in cahoots with the Crown.
And the only time I'm making a deal with the Crown is when I'm binge watching the series on Netflix.
What I'm going by is the evidence that the Crown Prosecution Service presented that the jury convicted her on and that Justice Goss sentenced her by.
And also, Lucy fits some of the parameters of previous data of known female serial killers.
So I'm just going by that.
But I've gotten all kinds of emails and notes and Twitter posts and stuff that tell me all kinds of things about me.
What's the issue that people have with you coming at this from a very well educated, I think you've got 1000 plus references of some kind in your book.
It's not like you're just making up some whimsical dark story, you're trying to assess this using the latest in scientific methods.
Thank you for saying that.
So absolutely. So I mean, I'm not, I'm not a popular media writer, I conduct academic research.
You're right, in the book, Justice Deadly, I literally have 1200 references.
And they're not like, you know, Zippy's blog of murder, I go into academic papers, I go into court documents, I go into birth certificate, census records, etc, etc.
And my team and I gather data to determine some of the quote unquote, typical parameters of female serial killers.
And we came up with we put in a publication from 2015 published in the Journal of Forensic Psychiatry and Psychology.
And so based on date, all these data that we looked at, we know some things about some female serial killers, and Lucy fits those.
So what would be my angle?
I don't know her, I don't want to know her, I'm just going by my, you know, quote unquote, expert informed opinion.
And I'm going by the fact that a jury of her peers sat through that entire trial and weighed the evidence and decided that she was the one who did this.
So I have no, you know, personal stake in the game other than to, you know, hopefully get killers off the streets or better yet prevent it before it happens.
What were the criticisms that you were getting from the people that were tweeting things at you or being critical of the work that you were doing?
What do you make of that motivation?
I imagine you've thought about why these people had such a visceral response to you just coming in to do analysis.
Sure. I'm not sure about, okay, so I can tell you what, again, they said I was stupid, blind, uneducated.
I mustn't have looked at the correct data.
I must be on the side of the crown.
I am half British, but I'm a United States citizen.
I'm down with the crown, they're cool, but I have nothing to do with the case that they presented.
And again, like I said, they even said, they don't like my American accent.
Okay, well, cheers.
Cheers to that. Now, why they would do that?
I mean, people just, when somebody's convinced something is true, they dig their heels in.
And even in the face of contrary evidence, they might dig in even further, and instead of addressing the message, as you know, an ad homme and a metac, they'll attack the person that delivered the news.
I'm just giving an opinion.
Now I also think, I wonder seriously, I wonder if I were a male researcher delivering this news.
If the receipt of such and the response to such would be different, I'm not sure.
That's interesting.
Why do you think it is that the entire world, it seems, is so interested in serial killers?
I don't think I'd really growing up ever thought of that.
And then this sort of flourishing true crime industry comes out, especially in podcasts and audiobooks and now Netflix documentaries.
And my feed on Netflix is just filled with different murder mysteries from the 80s and the 90s and stuff.
Where do you think this morbid curiosity comes from?
Sure, absolutely. So I'm sure there are many, many factors that go into why somebody might be interested in that phenomenon and the level to which somebody is interested in that phenomenon.
Me coming from an evolutionary perspective, because I'm a trained evolutionary psychologist, just what you said, morbid curiosity.
So I do believe morbid curiosity informs protective vigilance.
What does that mean?
We are pre -programmed to pay attention to the things that could hurt us.
Like, wow, look at that, right?
If anybody has ever, heaven forbid, passed a traffic accident, you're paying attention to it, can't keep your eyes off it, I think we are literally genetically pre -programmed to pay attention to the things that could hurt us so that we can take in information.
And I do want to add that this is very likely all unconscious, right?
You're not going to say, oh, my goodness, let me watch this latest documentary on John Wayne Gacy so that I can make sure he doesn't hurt me.
He's dead, right? So I just think it's part of human nature to pay attention to the things that can harm us.
So I started studying myself.
I started studying female serial murder, or serial murder, because I was interested in it.
I have traditionally studied romantic attraction between men and women.
One of my friends, Dr.
Thomas Bowers, was conducting a project on mass murder.
And I said, hey, Tom, can I be on your team?
I can add some evolutionary, you know, opinions to that.
Yeah, yeah, yeah. And then while I was doing that, a really great student named Erin came up to me and said, Dr.
Harrison, can we do an independent study on serial murder?
I'm so, oh, yes. Right.
I didn't even ask why or what or how or who or when.
Well, yes, let's do that.
Because, you know, it's just so interesting.
But I'll tell you what, as I got really into the topic, years and years of research, I'm really grateful for media outlets seriously like yours.
And there's some really authentic networks out there that want to uncover the truth.
But I do take exception to using the genre as some kind of morbid museum, like, like dripping blood down the wall or whatnot and drinking alcohol while talking about victims.
That's just not, I don't think that's very empathic to the victims and their families and their friends, which are considered co -victims.
Yeah, I guess it turns a crime into a recreation activity.
And, you know, you forget.
I suppose the even with Netflix now, they're taking real cases and dramatizing them beautifully with attractive actors, and it's shot very nicely.
And that really does I never even thought of this before, but it's a great point.
It blurs the line between something which actually happened and fiction.
And you go, well, it's a it's a true story.
Yeah, but I mean, like, was it as glamorous as this?
Did everyone have super smooth skin?
And, you know, I don't know, it's a it's a very interesting question to ask.
I absolutely agree with you.
And I could tell you that I have a colleague whose uncle was murdered, and it is a well known murder.
I don't feel the liberty to to to say which one it was.
I'll let her tell that story.
But she agreed to do a very popular podcast, not yours, Chris, you're a good guy, but she agreed to do a podcast.
And the victim was involved in the entertainment industry.
And it really did have good looking people around.
And after the interview was done, and my colleague spoke on behalf of the family, they pumped in music to the final cut and said, Oh, wasn't that a sexy murder?
Now, let me tell you, that really hurt this person's family.
My colleague couldn't believe they did that.
They said, I thought this was a legitimate interview, and I was representing the interest of the family.
And so you tell me, you know, when I get asked to speak to the murder club, and I kind of cringe, I just, you know, look to each their own.
But I do wish as a society, we had more, you know, I wish we had more empathy for the victims.
Then again, I'm researching and I'm, you know, selling a book that describes it.
But I really, truly hope I've put forward that message.
I'm trying to give out data out there so that we can respond to or better yet prevent these kind of things from happening.
What percentage of serial killers are female?
So no one really knows, but the estimate is one out of six, at least in the United States.
That's what I know about it.
How many, again, whatever it is, some joke about the only time it's a crime is when you get caught.
Of serial killers, we have either caught or whatever figure it is that we use as a total number.
How many is that per year?
What is one out of six -ish?
Are we talking about 10 people a year?
Are we talking about one person a year?
That's a really good point.
The truth is I don't know, but I can tell you female serial murder is very rare.
So since I've been studying this, which is probably 2014, so probably the past 10 years, the cases I've been asked to look at, maybe three or four.
Wow. Right. So that's...
That's not historical, right?
That's ongoing. So in the decade you found around about...
One was ongoing. Right.
I'm sorry. I didn't mean to cut you off, Chris.
Not at all. So you had asked ongoing.
So since my research trajectory emerged, there were about four cases that I became aware of.
For example, Red Amaze in the United States, Lucy Lefebvre in the United Kingdom, and there are, I believe, two more.
There was one case that I actually consulted on that I probably can't talk about.
They got her. They knew it was she.
They got her. The True Bill Ranjuri indictment came out.
She knew this, and she died by suicide before they could arrest her.
Gah, swinging a mess.
It's true. And I'm good friends with the lead detective on that.
I said, how do you feel?
I just wanted the families to have justice.
I said they did. I said you did your job.
Yeah, wow. What is the...
Let's get into the meat and potatoes of this.
Talk to me about the demographic of female serial killers.
Who are they? So is it okay if I refer to my paper here?
So we published a paper in 2015 where we took the data that we had.
The sample size we had was 64 female serial killers who committed their crimes in the United States, really, since there's been a United States.
So 200 and something years, please don't make me do the math on that.
And here's what we came up with.
She's likely white.
She's probably been married at least once, but perhaps several times.
Probably in her 20s and 30s, probably Christian, probably middle class, probably has committed her crimes in the suburbs.
She's probably employed, and there's a very good chance she's going to be a health care worker, like a nurse or a nurse's assistant.
About 44, 0 % of female serial killers are nurses or nurses assistants.
We know that she's very likely in charge of taking care of helpless others, so whether that's a mother or a nurse or a nurse's aide, so somebody who's vulnerable and can't fight back, a child, an elderly person, a disabled veteran, et cetera.
She's probably at the very least of average attractiveness or maybe even good looking, probably had some childhood problems herself with abusive parents, maybe some sexual assault, CSA childhood sexual abuse she experienced when she was younger, et cetera.
And the motives that we found, money was the number one motive, so money resources, but very close second to that was power.
And so let me just say this.
If I could do this paper again, if I could do this entire project again, which took a long time to do, I focused on primary motive, and if I could go back and reinvent this, I probably would have looked at multiple motives because I don't, after all this knowledge gained over the years, I don't think
you can really split it out.
I don't know if money and power might go hand in hand.
I could just say numerically money was the number one motive and power was the number two motive when we looked at this person's primary motive.
Okay. Let's get back to those demographics.
So they were moderately educated.
They were gainfully employed, typically.
Many were in marriages or in relationships.
So just immediately thinking to compare this to this sort of loner man on the street guy in a cabin, solo, sigma male danger person, the Ted Kaczynski of the world, sort of night stalker person of the world.
Sure. This seems like a big difference.
So using your evolutionary lens, why is it simply that there's fewer female homeless people?
Is it that there's something, the stasis and the foundation of a family gives a potential female serial killer the stability that they need to be able to go and commit a more outrageous crime?
Oh, sure. I think everything you just said could come into play.
Again, I'm an evolutionary psychologist, so I do look at sex differences and we do see profound male, female, serial killer sex differences.
We wrote a paper on that.
We published it in evolutionary behavioral sciences and we looked at stuff like, for example, men are far more likely than women serial killers, of course, to target a stranger.
Women are far more likely than male to target somebody familiar to them.
Again, primary motive for men was sex.
Primary motive for women was money.
Men tend to be undereducated.
Women tend to have at least some college.
That's not speaking to intelligence.
That's speaking to level of education attainment.
Just on the education point, what do you think it is that's driving more uneducated men or more educated women to commit murder?
I'll give you my birth science theory of why it might be from my perspective.
Low status men have less to lose.
And socioeconomically, if you know that you're a little bit further down the hierarchy, roll the dice.
Whereas for women, that's not as much of a driver.
Right. I think what you believe would play into what I believe in that a low status male is far less likely than a middle class or high class male to get a date or to establish a relationship.
And so there's this aberrant sex drive.
The other way we can look at it is like this.
And I haven't thought about this before, but when you were talking it made me think, is it somebody who is undereducated or is it somebody so pathological that they couldn't go through the educational system?
It's a selection effect.
They're just getting kicked out of it.
Right, right. So that just brings me to another male -female serial killer sex difference, which I'm not really sure.
Let me say this. Our data showed that at least 90 % of male serial killers had some form of mental illness.
In female serial killers, our data showed that 44 % had some form of mental illness.
Now we could say, wow, men are twice as likely to be mentally ill.
But I'm not so sure, right?
Because we have to visit the salience of diagnostic systems over time, whether this person actually was ever assessed.
I'm not sure. In fact, after conducting the research that I have, after assembling research to write the book, Just as Deadly, I'm convinced there has to be some form of mental illness present for somebody to commit these heinous crimes.
There must be. They don't think like we do.
You and I wouldn't do these things to babies or elderly people or women exiting a library.
You've got to be thinking aberrantly.
What did we say at the very beginning, this sort of allo -parenting, caregiver, typical mothering nursing type trend that women have, this predisposition that many women have, at least on average in comparison with men, that to me would suggest that in order to overcome that nature and do what is the opposite
of caring for, I mean, think about little girls in a school yard, right?
At least little boys are practicing warfare.
There's aliens or there's cowboys or there's whatever that they're waging war on.
But what are the girls doing?
They're caring for something, a small rabbit or a doll or whatever it might be.
We're playing hospital.
And Joyce Benenson's done tons of this work.
This happens really, really early on in life.
Right. Okay. That to me suggests that it's an even bigger jump from the set point, let's say, psychologically, of females to get themselves to the stage where they're prepared to take a life.
Sure, absolutely. So we do know that not all boys play with trucks and planes and not all girls play with dolls, but that's predominant.
I myself, I played with stuffed animals.
It's all good, right?
So absolutely. And we do know that in women, to me, it's undeniable there is a caregiving, there's a caregiving instinct in all of us, but there is a caregiving instinct.
And so again, I'm an evolutionary psychologist.
And what we say is that in evolutionary psych, behaviors evolve because that behavior led to traits and dispositions that made you leave more descendants, right?
So we have this caregiving thing.
People who had a caregiving instinct left more descendants.
But we also say in evolutionary psychology that there's this poly distribution of inherited traits.
So I'm going to draw the bell curve for your viewers, right?
So if you took a statistics class, remember the bell curve.
And let's say moms, even nurses, right?
Most of them are right in the middle, the right amount of caregiving.
Let's go with moms.
The right amount of caregiving, most of us turn out okay.
But if you look in the bell curve and you look down all the way in one tail, you'll see the extreme people who are overbearing and over anxious and they monitor child's every single move and they get sick to their stomach when their kid goes to the prom or something like that.
All right, that's one tail.
What about all the way in the other end of the other tail, sorry, the other end of the other tail, we have people who are abusive, people who are neglectful, and then deep down in that other end of that other tail, we have people who kill their own kids, right?
So there's this caregiving instinct gone awry.
And I do believe that is the case.
Now, you mentioned something going back to nurses as female serial killers.
I actually have dated a nurse.
I've actually dated a neonatal intensive care nurse.
And when I told her about Lucy Lepi, she couldn't believe it.
She said, how could somebody who has devoted their whole entire training and life harm the person to which they took an oath that they would help?
So how does that happen?
And we don't really know.
I could say that right now, not my research, but some other research has suggested that I don't know if a nurse goes bad.
I think maybe sometimes that personality type goes into the field.
I don't know if it's to have the control.
I don't know if it's to save myself.
I'm going to have the urge to kill people.
Let me help them. I'm not sure.
But I do think maybe that kind of person goes into the field.
Now, that being said, please let me say this.
Almost every nurse or almost every mom that's ever lived and will ever live will never hurt somebody like that.
Let alone become a serial killer.
We know that, but that's just speaking to the extreme.
And that's the research field that I've entered.
I wonder whether it's a misfiring Angel of Mercy thing, if you can somehow convince yourself if you've spent all of this time caring for young people or old people or something else, that I don't know.
What do they say about...
In retrospect, does it seem like they think they're doing something good?
Are they doing it for pleasure?
I don't understand the money that you get from killing a child or an old person.
Okay. So if... And this is really awful, but I've created some case studies from history.
I put the data together where there were people that...
Let me give you an example.
There was a female serial killer in Connecticut, United States at the turn of the last century.
So civil war time in the United States and thereafter.
Her name was Lydia Sherman.
And she was a serial killer.
She killed her own kids.
She killed her step -kids.
She killed several husbands, gave them arsenic.
And when she finally admitted, yeah, yeah, I did this, why did you kill your kids?
Well, my husband lost his job and the little kids couldn't really do anything.
They couldn't do anything for me.
They couldn't do anything for themselves.
So I got them out of the way.
She quote unquote, hurried them into eternity was the quote.
So getting them out of the way.
Is that Angel of Mercy in some weird reimagined, terrible angle?
I guess. Now in terms of nurses, I have read cases where somebody say, well, they were sick.
I was doing them a favor.
Yeah. Right. But take for example, the case of Kristen Gilbert, who was a serial killer from Massachusetts, United States in the mid, maybe the late eighties, up to the mid -1990s.
There was one disabled veteran she killed.
His name was Kenneth Cutting.
He was a really nice guy.
He was in his forties in the hospital.
She asked her supervising nurse, if this guy dies, can I leave early and go home?
And he wasn't on death's door or anything.
And the supervisor said, sure, sure enough.
Kenneth died by the end of her shift.
She caused him to have a heart attack.
So that's just getting somebody out of the way.
So Angel of Mercy, maybe we have experienced that in our society in times, but I don't buy it.
Whose mercy? Whose mercy are you defining?
Whose mercy are you executing?
Yeah, it's an interesting one.
The single versus married thing, why do you think that, again, women, is it just that on average women are more likely to be married than men at this age?
I'm not sure. That's a good question.
So one, I guess reason at the forefront would be that women could kill their husbands, right?
So they're going to get married, and they're going to kill him, and they're going to take his insurance and his inheritance and everything else, ride that out for a while, get married again, let's take him, take his stuff, get married again, take his stuff.
Lydia Sherman that I was telling you about, her nickname was the Derby Poisoner.
That's what she did.
She killed this husband.
I'll get him out of the way.
Then she married an old widow widower, and he was dead within months.
Then she married Mr.
Sherman, who was fairly wealthy, and she got him out of the way and attempted to collect the insurance money, but she didn't get away with that one, and they went back and solved the other crimes.
So that might be one reason for the multiple marriage, marriages, multiple targets.
But what I wanted to go back to, if I can, is right in the beginning you were describing, well, they're married, they're sort of educated.
That's exactly who you wouldn't suspect, right?
Like if I said, Chris, describe somebody who is not a serial killer.
Well, grandma who stays at home, makes cookies, maybe has had two marriages, maybe has three kids, goes to church, sells stuff at a bake sale, goes to synagogue, sells stuff at a bake sale.
That's the person you wouldn't suspect.
Hiding in plain sight.
Hiding in plain sight, exactly right.
What about life events potentially contributing or priming female serial killers to be more likely or psychosocial factors?
This is interesting.
So when I documented, I did that analysis more thoroughly on female serial killers.
We found everything from mothers who died when they were young, abandoned them, fathers who were abusive.
We found physical abuse, sexual abuse, emotional abuse.
So we did find that in female serial killers history to a degree greater than chance, right?
So more so than someone in the general population would experience.
But let me tell you something that I don't necessarily have data on that I probably could gather data on.
But when I wrote the book, Just as Deadly, I put together about 27 different case studies.
And I tried to write about the psychology and whatnot.
And what I did was I wrote about five men and then the rest were women.
And different female serial killers are.
And I can tell you in almost every one of those cases, that person was severely sexually abused when they were younger.
And I've heard people come out of the woodwork and say, no, it's a myth that serial killers were sexually molested.
No, it's not. No, it's not.
I have read this. Now, again, let me stress, for people who have had that terrible thing done to them when they were kids, almost everybody would never grow up and hurt somebody else, let alone kill them.
But if you want to see a common denominator in both male and female serial killers, you see this profound CSA childhood sexual abuse.
I've seen it in the data.
The interesting thing there is, as you identified previously, and as we're going to get into in a bit in terms of motives, men a lot of the time are killing, it's in and around sex, sexually motivated in one form or another.
But for women, that isn't.
But for both men and for women, childhood sexual abuse is predictive of becoming a serial killer later in life.
So what that suggests to me is there is what seems to be most likely, childhood sexual abuse does not make men more likely to use killing as a sexual weapon because you have a split test, which shows that women don't, they still do.
So what is it doing?
The way that you see the world, this reactivity toward aggression, this requirement to use physical force in order to be able to enact your will, it seems like that.
But I mean, that's fascinating, right?
That you basically have the same scenario, both predicting the same outcome, but the way that the outcome is deployed is motivated in a different way.
Absolutely. You said that brilliantly.
You're absolutely right.
And when somebody experiences that violation when they're younger, I mean, it's shown in the research that I don't conduct, definitely behavioral neuroscience research, your nervous system literally rewires itself.
So imagine somebody who is violated when they are a child.
Certainly they are more reactive.
Their nervous system is more sensitive to any kind of aggression, et cetera, et cetera.
It's terrible. It absolutely changes who the person is.
And you're right. And male serial killers, again, I don't study them as thoroughly as I do female serial killers, but it is my understanding.
Most are sex crimes.
And they might start out as experiencing a paraphilia.
So what that is, is like an abnormal sexual interest.
Maybe in, like, I'm not saying it's abnormal.
Do what you need to do.
But there are psychological classifications that would say, for example, a shoe fetish is abnormal, et cetera.
So it might start out with that.
And then it might eventuate to watching somebody get undressed.
And maybe that doesn't fulfill the gratification or the fantasy.
So it eventuates and ascolates right to attacking somebody.
So we see that. There was somebody by the name of Jerome Brutus, who is a serial killer.
And he started off with a shoe fetish.
Then he started killing women and literally keeping their legs, literally severing their body parts and keeping their legs, sexually assaulting them and then keeping their legs to show off his shoe collection.
And so that's a really, really worst case scenario, right?
But it happened. And again, serial murder is rare in female serial killers or even rarer, but it does happen.
Do female serial killers take trophies?
That's really interesting.
So my colleagues and I, Stephanie Winkel, John Black, Claire Allie, and I are looking at that.
It's a study that we're currently working on.
We've not gotten it published yet.
But yeah, we do see that males are very likely to keep trophies.
More likely than females are.
Here's the thing. I actually didn't think as many female serial killers would keep trophies.
But again, these are new data.
We don't have them released yet.
But I did see that they did.
Now, it depends on your definition of a trophy.
If a male serial killer keeps it, is it to being frank masturbate to it, to relive the sensation, the sexual gratification of the crime?
It could be some kind of glorification totem and whatnot.
I've found women they might keep like a necklace or a lipstick or something.
And I don't know if that's a trophy or that's because they like it.
This is a nice lipstick.
Why should I throw it away?
So I'm not really sure about that.
But I saw trophy keeping in both sexes just a lot more in male serial killers.
There's some other teams that say that they didn't witness that in the data, but my team and I did find it in the data.
What about substance abuse?
I have seen that as well.
Again, I don't have those data in front of me, but I have known cases of female serial killers who had drug abuse problems.
There's one female serial killer who used to get...
I better not say a name because it's not coming to me right now, but she had profound substance abuse.
She used to hide drugs and she would wear her hair in curlers like how women curl their hair and leave the curlers in.
She would hide pills in her curlers and in her toilet paper in her bathroom.
She had a really profound substance abuse problem.
But I don't see that as like if you asked me to pull up my data from the 64th female serial killers we initially studied, I didn't really see that as a salient factor.
Have you got any idea how common that is among male serial killers?
That they're drinking and killing or taking drugs and killing or that they're self -medicating from maybe some psychological disturbance?
I would guess again, what we need to try and separate out here is what's the base rate difference on average between the sexes.
Again, more women are caregivers, but probably not.
It shouldn't come out at 40 % of them as being caregivers.
You know what I mean?
I'm trying to work out.
Oh, you're exactly right.
So I don't know. And you're right, not only male versus female serial killers, but male serial killers versus men in general and female serial killers versus females in general.
So I don't know that.
I have seen because I've studied some people in depth, like, oh yeah, she did that.
Or yeah, he did that.
But I don't know the data overall.
It seems to me though, that would be not a cause, but one of the effects of whatever went wrong initially pathologically trying to numb myself and then committing those crimes as well.
But I don't really see the drugs and alcohol as fueling the crime.
So that's, we have this psychological disposition, maybe disturbance downstream from that.
Lots of things happen.
Yeah, you're exactly right.
Self -medication, maybe drinking, another one of them maybe being killing lots of people.
Okay, so let's get on to victims.
Who do female serial killers kill?
What's interesting about that?
What's different about that?
Okay, so most commonly a female serial killer will have both male and female victims.
Most commonly a male serial killer will have female victims.
But like we said before, women tend to kill elderly people, people of, you know, of age, infants, or people with some kind of disability or illness that all of these people can't fight back.
That's the common denominator.
It's very predatory.
Absolutely. That's a good way to put it, absolutely.
Sure. Why? Why? Is that safety?
There's no retribution?
There's no retribution.
And wouldn't one be less likely to be caught if somebody who was in the hospital for an illness dies, couldn't it be attributed or explained away as a product of their illness or injury, or a baby who dies?
I mean, again, I studied some female serial killer cases from back in the day.
It wasn't unusual for infants to die back then, right?
There was a higher infant mortality rate.
So I would think that the victims could be explained away.
Also, for women who killed their husbands back in the day, it wasn't unusual for somebody to die of stomach disease or whatnot.
And so these women tended to use arsenic and other poisons that would mimic stomach disease, heart attack, et cetera.
So I think it's the victims that people might not suspect.
Are they ever sexually motivated from women?
That's a very good question.
I have not really seen that frequently.
I've heard anecdotally that maybe one or two might have had some sexuality going on there.
For example, again, I didn't see this in any official reports or newspapers or anything, but there's some rumors out there that Jolly Jane Toppin, she was a nurse from Boston, the Boston area of the United States from the turn of the last century, like the 1900s.
And she used to give her patients central nervous system stimulants and depressants to put them to the brink of death, bring them back to life, and she wanted to lay in bed and hug them as they died so she could feel the breath going on to them.
And there was rumors that she may have kissed some of them or mounted them.
That was just some rumors, but I've not really seen that officially corroborated.
I've read reports where she actually said I got into bed and held them to experience their last breath and she thought that was a glorious event.
So the power involved there is interesting.
What's the split of male to female victims for female killers?
That I'm not sure. Give me one second to look at my paper and see if I have it written down.
I'm just interested.
I'm wondering whether the split gets skewed when you get rid of children, when you get rid of infanticides.
Oh, that one I know for sure.
Men are far less likely than women to kill children only, far less likely.
I've seen it done, but far, far less likely.
Oh, that's a good question actually.
Are women more likely to kill young people like children than men are?
Let's see. So in terms of killing only adult victims, it's equal.
About 49 % of male serial killers and about 49 % of female serial killers, both adults and children, 47 % male serial killers, 23 % female serial killers, only children, about 4 % of male serial killers and about 27 % of female serial killers.
So you've got the infanticide killer stuff going on there.
How much of that have you got?
Any idea? Again, if you were to separate, how often is it for a mother to kill her own child as part of a serial killing career?
I'm aware infanticide is a thing that happens from mothers to children, but doing it as a serial offensive.
Sure. Absolutely. So going back to the definition of serial killers that we use, three or more deceased victims with a cooling off period and use the term cooling off, however you want, just the time gap of at least one week between victims.
So we might have somebody, a mom with Munchausen Syndrome by proxy, we call it these days factitious disorder imposed on another who would kill child after child, year after year, and they would be considered a female serial killer.
How often that happens?
It does happen. It's not very often.
There was a female serial killer named Mary Beth Tinning in Schenectady, New York, United States, and it is suspected that she killed at least eight of her children.
I don't think she was convicted of all eight, but the story goes, they think that her first baby died, natural causes, and that maybe she saw all the attention she was getting.
And so the next baby and the next baby.
And the rumor was that she had some kind of nursing knowledge.
So she knew how to mock and present symptoms and that she would back then, even in the 70s and 80s, medical records were not as centralized as they are now.
So she would go to different hospitals with these different infants.
There was a book written about her.
And the author of the book, and I'm sorry, the name escapes me, but it's a very good book.
She said that reports say that at each funeral, Mary Beth would get all this attention.
And she seemed to quote unquote, be having a good time at the funeral of the babies, everyone saying, Oh my goodness, what a poor mom, what a good mom you are.
And finally, somebody called the hotline and honest, anonymously and said, aren't you going to do anything about this?
And they looked into it.
And finally, with the death of Tammy Lynn, her last child, they, they, they caught on.
In fact, Mary Beth allegedly tried to kill her own husband, and he didn't even really do anything about it.
But child after child, year after year, suggests this person would be considered a female serial killer.
Let me add one thing about the Mary Beth Tinning case.
It's the first modern case that I've been reading about these for 10 years now.
It's the first modern case where I saw the prosecution and the defense say, wow, there's something really mentally wrong with this individual.
They need help. Versus in the past, in the forties and the fifties, I've seen, you know, retribution, like let's put this person to death.
In this case, I've seen, wow, there's got to be something really wrong for somebody to do this.
Let's try to get her some help.
This is the first kind of compassionate case I saw.
Again, I'm not trying to say I feel bad for serial killers, but if, you know, some things have happened to these people.
And if I may, if I may just add this, Chris, it's tough because I'll give talks and I'll say there are some serial killers I feel bad for.
And I, I don't want that taken out of context and then canceled over it because I have really a lot of empathy for the victims.
We said much worse things on this podcast.
There's much. Okay, it's good.
But let me, let me say this.
Let me tell you a story.
What if I told you a story of a young boy who, um, his father named him a very masculine name, but it turned out he was a little bit feminine.
So the father used to beat the crap out of him, beat him in the head until he was unconscious.
This boy was molested when he was eight, eight at age five by a female babysitter.
Little bit later when he was about eight years old, he was molested by a male local contractor and his sister corroborated these things.
Um, his mother was so physically abused that the father would beat the hell out of both the son and the mother.
I wonder if somebody would feel sorry for that person.
I do. Right. But that person is John Wayne Gacy.
So if I said to you, do you feel bad for John Wayne Gacy?
By the way, he killed at least 33 young men and buried their remains under his house and threw them in the river.
You don't feel bad for that.
But if I told you the story of that boy that they called Johnny back then, you'd say, Oh my gosh.
Right. Now, again, most people who were abused never ever would harm somebody like he did.
But we look at that and we say, wow, you know, if somebody had come in there and helped Johnny and his mom, maybe those 33 young men would still be alive.
So I think that's, you know, something, yeah, we want to solve crimes, but as a psychologist, let's solve the psychology.
Let's solve the riddle and we can get in there and maybe help people before they go down this path.
Can we talk about the motives, but using an evolutionary lens?
Oh, sure. You said money, power, and then give an evolutionary perspective to that.
And then can you compare that as well with, uh, the male motives?
Absolutely. So, uh, I'm an evolutionary psychologist by training actually my degree says biopsychology, but I'm an evolutionary psychologist.
It all comes down to sperm and eggs.
All right. It always does.
So men produce millions of sperm on a daily basis.
Women have all they're born with all the eggs they'll ever use.
The probably only ovulate maybe a couple hundred times in their lifetime.
So if you look at reproductive potential, men could father as many people as they could find reproductive partners.
Women, you're only going to get pregnant once, right?
So men have a lot more chances for reproduction compared to women.
Men have a higher sex drive compared to women worldwide.
I'm not saying you're going to meet a woman who's not the horniest person you've ever met in your lifetime.
I'm not saying that, but on average, men have far greater sex drive than women do.
And we in evolutionary psychology attribute that to underlying biological differences.
Okay. So how does that play into serial murder?
Like, okay. So women with these very limited eggs, very limited reproductive opportunity in the ancestral environment, it would have benefited a female to pair with somebody who had a lot of resources, right?
Because not now, right.
We are women hear us roar, but back in the ancestral environment, you females were far more slender and helpless and whatnot.
It would have been really reproductively advantageous to pair with the alpha male who had a lot of access to resources and territory.
So men seek sex, women seek money, worldwide women prefer people with resources.
What are the number one motives for serial killer?
Sorry about that. One more time.
What are the number one motives for serial murder?
For men, it's sex for women, it's money.
That didn't surprise me at all.
Absolutely not. And then there was another perspective that I had and it takes a little bit more, you gotta bear with me on this one.
But my team and I came up with the hunter gatherer hypothesis of serial murder.
And it's not the only explanation, trust me, but it could be a part of the explanation for serial murders in that it is thought that anthropologically speaking, we evolved from societies where men did the hunting and men did the hunting and women did the gathering.
And so what do we see?
Male serial killers as hunters.
They stalk victims, unfamiliar victims.
They write down their times of day and where they work and their friends and they follow them just like a hunter would hunt prey and they keep trophies like a hunter does.
Women, use this one a little bit more figuratively, they gather victims.
They gather the people around them.
They look around, who is around me?
Let me kill them. And then they gather prophets as well.
So we did come up with the hunter gatherer hypothesis and everything we tested in our study showed to be so.
So then target strangers, they kill people outside their birthplace, et cetera, et cetera.
So there is some evolutionary perspective, but let me add, I know it is not the only factor.
You have to consider components, developmental trajectory, parents, school, childhood illness, society, gender roles, time in history.
You have to consider all of these things to think about what makes a serial murderer, but I do think there is an evolutionary component.
Yeah. It's interesting because you hear that a wife was killed was the first place that you look, the husband.
Right. Sure. Well, by your evidence, it seems that men are more likely to kill strangers than they are to kill their intimate partner.
That is interesting.
However, the number one motive, last time I checked in North America for murder was male perpetrated jealousy.
So there you get the intimate female part.
Male perpetrated jealousy.
What's that? Yeah. So I'm sorry.
So a man kills a woman because he's jealous of something.
Last time I checked the statistics, I might want to go back and check the statistics, but in North America - The guilt is rejected.
I'm falling in state as I - My woman is cheating on me, that kind of thing, or I think she's cheated on me.
And David Bus and colleagues have done a lot of research on that.
How do women kill? What are their methods of choice?
Poison. So a lot of people call those passive methods.
I'm not sure. If you've ever read about what arsenic does to somebody's body, chronic, and acute - What is it?
What does it do? Let's say I take some arsenic.
Oh my gosh. Let's say you take some arsenic.
Well, you're going to get encephalitis.
Your brain is going to swell.
All of your internal organs are going to swell and then fail.
Your gastrointestinal system is going to bleed.
You are going to vomit blood.
You are going to have bloody diarrhea.
You are going to be doubled over in cramps until you die.
So we don't want anybody to do that.
No, thank you. It's horrible.
It's painful. And it might not even be that day.
It might be days of this person's suffering.
It's horrible. It's a poisoning, a variety of different ways that they use it.
I'm going to guess.
Right, yes. And so I'd say poisoning, but I use actual poisoning like terro rat killer, ant killer, that kind of thing.
Arsenic, that used to be able to buy the ounce at the apothecary back in the day and prescription drugs.
So they might inject somebody with insulin and induce a heart attack and then they die by heart attack.
And if they're in the hospital anyway and they say, Oh wow, hey, he had a heart attack, then people might not suspect it.
So yeah, so it could be poison in terms of illegally used poison or pharmaceuticals used to a poisonous efficacy.
I wonder if much of the reason that you have this higher prevalence of caregivers and nurses is simply that they're around the weapons that they're going to be able to use.
It could very well be.
So I have a good friend who is a nurse, somebody went to high school with and she's been a clinical nurse 25, 30 years.
And I called her. I said, Why?
Right. Why? And she said, Maris, don't take this the wrong way.
But right now I can tell you a hundred ways I can kill you when no one would ever know, because that's one thing that comes to my mind.
She says, no one would know.
We know how to do these things.
So they have the means and the access.
And again, if somebody dies in a hospital, it's not the most peculiar thing that's ever happened.
So they have the means to get into it.
Exactly. What? Oh, you've spent all of this time studying a lot of female serial killers, of all of them, who has been the most outlier psychologically that you found?
I would say the outlier is Aileen Wuornos because she shot men, left their bodies in the woods to decompose and rob them.
I mean, so you have the financial motive there.
But I mean, she was really abused.
She had some mental illness.
She was a psychopath, etc., etc.
So I don't know. She was really the outlier there.
Again, I think even in the absence of any diagnosis that I have read, you've got to be mentally ill to do something like this.
So I don't know if there's any psychological outliers, but if you name a mental disorder, I have seen it in female serial killers, schizophrenia, bipolar disorder, anxiety disorders, Munchausen syndrome by proxy, now called factitious disorder imposed on another.
So if you name it, it's borderline personality disorder.
It's represented in serial killers.
What about female serial killer wives of male serial killers, like killer couples?
Interesting. So I never studied killer couples.
And I'll tell you why.
I wanted to study psychology and I wanted to know what we call the autogenic motive coming from you.
So if this is my husband and we're killing, how do I know who it came from?
How do I know who who thought of these things or who persuaded whom to do what?
I don't know. So I never studied paired serial killers.
There is a pair I'm thinking about.
I've not studied them, but the pair from the United Kingdom, was it Anne and, sorry, Mira Hadley, is it?
Yes. Okay, right. So what's really interesting about them, and I just maybe go on with a little tangent here, but please follow me.
I don't even really remember his last name, but I remember her.
And from what I recall, and I have some friends from Britain, have some family from Britain, they tell me she is one of the most hated people in Britain.
I'm like, yeah, but wasn't it Ian's idea?
And they're like, yeah, but people hate her.
Why? I think because she violated the female role.
She was a good looking woman who enticed kids to go on a journey or whatever those awful people did to those kids.
And people hate her more for being the accomplice than they hate him for coming up with the crimes.
He chopped somebody up with an axe, right?
But they hate Mira Hadley.
That's the number one.
It feels like she's contravened some sacred sort of protector code.
It's almost like, I guess, again, it's sort of the public perception thing that men, we expect that men are more likely to be serial killers.
So when you see a woman assisting a man in doing something you already know is heinous, you feel like it's almost double heinous in a way.
Oh, absolutely. They really do.
I just don't want to get her name wrong.
Mira Hadley. That's it.
Because people say there's the lady there with the book but doesn't know who Mira Hadley is.
Talk to me about the socio -cultural environment that we've got at the moment and our sort of living setup.
Again, if you're taking an evolutionary lens with this, we are in a novel environment, ancestrally, right now.
What do you make of that for the persuasion or dissuasion of killers, male and female?
The thing is, I don't think it is.
So again, I've studied female serial killers at length compared to my study of male serial killers, which I've studied somewhat.
And they got away with it largely because their methods were undetected for a long period of time.
I think we have increasingly sophisticated medical examination techniques, medical recording systems.
I mean, somebody who kills somebody, if they died of arsenic poisoning, we're going to on the first try.
So I really think that's going to dissuade female serial killers.
That being said, that's the kind we're used to.
I don't know, there might be some kind of woman that does these things and gets away with it that we haven't caught or written about.
Now, in terms of male serial killers, in terms of the typical profile of stalking and killing strangers, I'm not sure.
Think about the victims being so interconnected in this day and age with social media.
And I'm tagging myself here and I have cameras all over my house.
I'm not so sure it would be easy to get away with that.
And again, to meet the criteria for serial killer, it would be three or more victims with a cooling off period of one week in between or a timeout of at least one week in between.
So even if somebody was horrible enough and stupid enough to kill the first person, are they going to be able to get away with it the second and the third time?
Yeah, I really think about this a lot, especially given my nighttime penchant for watching Netflix true time documentaries and stuff like that.
So much of this is, you know, it's 60s, it's 70s, it's 80s, it's out West somewhere in Alabama or wherever the fuck it is that it's going on.
And I was like, why I don't hear much about modern day serial killers.
Is that just that forensic techniques are so good that one, potential serial killers are much more dissuaded from starting or two, they're so good that after the first or perhaps the second, they don't get chance to get to the third because they've been popped by some great investigator like your friend,
the detective. Right.
It could very well be.
I think you're on to something.
You're absolutely right.
And also, I mean, what about internet detectives, right?
Put a picture on Facebook or Twitter and say, catch this person.
They didn't x, they're caught in 20 minutes.
Right. So I think you really can't get away with stuff these days.
I wouldn't even try.
I wouldn't recommend it.
So I do think the detective work and the science is there to prevent or at least catch before someone eventuates to the level of serial murderer.
That being said, let's hope not.
And I also know that if people really want to do something awful, they will.
I don't want to go down this slippery slope, but honestly, there are mass murderers who, if they don't have guns, they set a house on fire or they push a car in front of a train.
They'll stab you. They'll find a way.
Right. So, yeah. So this is, we're an hour deep, so I can say all of the spicy things now.
You know how there is some good evidence that women commit or attempt, should I say suicide more than men, but men are more, for want of a better word, successful.
Yes. They complete at a higher rate.
I wonder whether, and this could go either way.
It could be men or women.
Men or women are less successful at not being caught as serial killers.
You would imagine there's sex differences in everything, pretty much.
So let's say, for instance, I would guess on average that females are more likely to be better at hiding their tracks, being conniving, planning, doing that sort of stuff.
So maybe the one in six number is that they are overrepresented because their failure rate, the amount of times that they kick some invisible trip wire, that a man who being a little bit more clumsy, less planned out, less sort of calculated in the way that he goes about his serial killing ventures.
I get the sense that maybe they're overrepresented because they're actually quite good, that disposition helps them.
Absolutely. So it's interesting.
I collected those data twice, and once the data showed that women got away with it longer.
And then the second time I did another study, it was just about equal.
And I have those data in front of me.
The killing span, we called it, the main year's killing.
For men, it was 8 .7 years.
For women, it was 7 .8 years.
So just about equal.
So they get away with it.
But you're right. I mean, if a male serial killer is sexually assaulting victims and leaving this trail of unfortunate dead bodies around the town, you're going to say, whoa, there's somebody there.
Let's catch them. They're going to work really hard at it versus female serial killers.
If this is awful, but babies dying in a hospital, it takes somebody to go, hold on, wait, there's a statistical anomaly somewhere.
Let's go back and check it out.
People don't just normally turn up with axes in their heads, but babies do sometimes die in hospitals.
Yeah, exactly. Exactly right.
So it seems like we have to catch a male serial killer, but we have to detect a female serial killer.
Oh, that's so great.
That's so lovely. And I think there's a difference there.
How cool. Is there anything else that we haven't said from the sort of evolutionary lens perspective thing around female serial killers?
Any unclosed loops?
I think I'd like to close up with this, and it might not be evolutionary, but I conducted research to be able to write my book with Cambridge University Press, but then I learned from writing the book.
And I know for sure from the data that I've seen and from the case that I worked on that we need more police resources.
So the world is not like CSI where you send specimen down to the lab.
And my friend from the FBI says it's hot men and women analyzing DNA to a banging musical soundtrack.
The world doesn't work like that.
They need money for these tests.
The police organizations sometimes don't have these.
We need more money for police and detective work.
We need more of it.
Secondly, we need more psychologists, right?
Because let's say somebody intervened back in the day.
Eileen Moronos was so sexually abused and raped when she was younger.
She accidentally got set on fire.
Her grades went down in school and the school called and said, hey, can we give her counseling?
Nope. Well, if she got a case worker, maybe things would have been different for those seven or eight men that she killed, right?
So we need more psychologists to get out there and intervene because if something bad happens to someone, the earlier you get there, the better.
According to psychological data, you can treat trauma.
If at all, you could give a better shot at it when it happens.
If somebody's a kid, when you get right there and do it right then and there.
So we need more psychologists and we need more, we need more psychologists and we need more police resources.
And that might tackle the problem.
Well, you may have inspired some fledgling criminal psychologists or detectives to get into the world of female serial killers today.
I hope so. I hope they take what my team and I've done and do it on a grander scale and create change, you know, make, you know, stop crime, help people where they need it.
I really hope so. And thank you for saying that.
I appreciate you. Marissa Harrison, ladies and gentlemen, Marissa, why should everyone go?
They want to keep up to date with the stuff that you're doing.
You can check out my faculty webpage, Penn State Harrisburg, or you can take a look at my book, Justice Deadly, The Psychology of Female Serial Killers, Cambridge University Press 2023, but the paperback edition is coming out soon.
So it's available on any retailer.
Thank you so much. Congratulations.
I appreciate you. Thank you.
Thank you, Chris.
