“You are the monster that no one sees coming,” U.S. District Judge Thomas Kleeh declared at the 2021 sentencing of Reta Mays, a nursing assistant who murdered seven men aged 81 to 96.
“It was almost the title of the book,” Marissa Harrison, Ph.D., an evolutionary psychologist and author of Just as Deadly: The Psychology of Female Serial Killers, says of the quote.
Dr. Harrison not only believes that female serial killers are understudied—but underestimated in brutality and possibly in numbers, often hidden by the stereotypes of nurturing mothers, selfless healthcare workers and helpless widows. Her research spans centuries, covering more recent female serial killers, like Mays, to a killer, Belle Gunness, who met her victims through newspaper “Lonely Hearts” newspaper ads in the late 19th and early 20th century.
Dr. Harrison’s previous research interests include the analysis of “attraction, kissing and declaring love.” But she became an expert on darker topics when she joined a colleague. Tom Bowers, associate professor of psychology at Penn State Harrisburg, in his research on mass murder. Soon after, Dr. Harrison assembled a team that included Dr. Bowers and undergraduate student Erin Murphy, to collect data on female serial killers in the U.S. and saw just how “very little empirical research there was on female serial murder.” Her interest in this topic deepened over the years and resulted in long-term study.
A&E True Crime spoke to Dr. Harrison about the most surprising thing she’s learned about female serial killers—and how she was impacted by victims’ stories.
Are female serial killers ‘just as deadly’ as male serial killers?
I’ve gotten some pushback on the title because it’s documented that male serial killers have more victims. First of all, dead is dead. Secondly, look at some of the individual female serial killers. Jolly Jane Toppan—authorities put her killings in the 30s. But she estimated that she killed over 100 people.
[The doubt] falls under the umbrella of, ‘Women don’t do that.’ Well, yeah, they do. And some studies, including at least one of my own, show that they get away with it longer, too.
Your approach to this book was very academic. Why was that important to you?
There are a lot of books out there about serial killing, particularly on male serial killers, [but there’s] not a lot about female serial killers. And almost everything I picked up was not referenced or keeps referencing the book that came before it, which didn’t have any references.
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I’m a psychological scientist. If I make a statement, I must back that up. I wouldn’t have it any other way. So, in the book, there are about 1,200 references. And those include direct, valid media sources like newspapers—not blogs, not Wikis—and court reports. Some of the data I collected myself, and then I read papers from scholars across fields, not only serial murder scholars like Eric Hickey, Frederick Toates and Enzo Yaksic. I reviewed scientific papers from experts in clinical psychology, developmental psychology, biopsychology in general and sociology, to try to gain scientific perspectives on why somebody might go down the path of serial murder. I really wanted to present as scientific and well-rounded a picture as I could.
What surprised you the most during your research of female serial killers?
This is not going to make me popular, because when I was done, I felt bad for many of the female serial killers. Of course, I feel worse for the victims.
In the book, there are about 30 case studies—maybe 24 or 25 of them are female serial killers—and something bad happened to these people in almost every case. And I know there are people out there that refute that, but I have 30 examples for you. These people were abused when they were kids—beaten on the head, molested. They needed help, and they didn’t get any kind of help. And listen, everybody who has bad things done to them doesn’t turn out to be a serial killer. I know that. But what if these killers had gotten some mental health help along the way?
Who is a prime example of someone who didn’t get the help they needed?
Aileen Wuornos. She was raped by her grandfather. Her father died by suicide. Her mother abandoned her. She had an incestuous relationship with her brother. A school counselor called her grandmother, who was her custodian at the time, and said, ‘Can we get Aileen counseling?’ Her grandmother said no. Aileen had mental illnesses.
If her grandmother hadn’t turned down that early intervention, maybe seven men wouldn’t have been shot to death.
In the book, you share how the victims’ stories impacted you. You wrote in the preface that after writing one description of a crime, you had to take the rest of the day off.
I had to go look at pictures of puppies. I really did.
I started doing this research in about 2014. And I’ve not become desensitized; I’ve become more sensitized.
I studied mostly female serial killers, but I studied male serial killers for comparison. When I read about Josephine Otero—who was a little girl, a victim of [Dennis Rader, also known as] BTK—I started to cry. And then there was the elderly woman that Dana Sue Gray beat over the head to take her credit card. [Gray] almost decapitated her and how do you not react to that? I felt like the victim was my grandmother.
I started this research off saying, ‘Oh, this is really interesting.’ But when it’s not a phenomenon—when you read about the people… [it’s different.]
Reta Mays killed veterans in a nursing home in West Virginia. Norma Shaw, the widow of one, died right after her husband, of a broken heart.
I do think [this sadness] shouldn’t be swept under the rug. I need to feel these things. I owe it to the victims. And there are details I leave out so as not to revictimize anyone.
Do female serial killers have different motives than male serial killers?
For men, the motive for serial killing is often a loss of status or something sexual. For women, the most common motive is financial gain—but you still have other motives like power-seeking or ‘missionary’ killing, an ‘I’m doing the world a favor’-type thing. And I don’t think those motives are necessarily mutually exclusive. There’s no study that nails serial killers, per se. But there are a lot of frameworks that attempt to categorize male serial killers, and female serial killers just do not fall into them neatly.
Many female serial killers were in caretaker roles. Multiple killers you write about were nurses.
One of my dear friends was a clinical nurse for a long time. And I asked her ‘What do you think of this [phenomenon]?’ And she goes, ‘Don’t take this the wrong way, but right now, there are 100 ways I could kill you, and nobody would figure it out. That is scary, right?’ So, the knowledge is there. I hope it doesn’t sound disrespectful to our hero nurses. It’s something I’m very interested in studying further.