FBI agent who inspired Clarice Starling reveals what it’s like working with serial killers

Getting a phone call from a serial killer is the kind of thing most people would find unsettling.

For Jana Monroe, it was just another day at work.

It was the early 1990s and Monroe, who had been an FBI agent for just over five years — and was the only woman in the FBI’s Behavioral Sciences Unit at Quantico, Virginia — picked up her office phone to be greeted by Edmund Kemper.

The notorious serial killer, nicknamed the Co-Ed Killer, had slaughtered eight people in the 1970s, including a teenage girl and his own mother.

It wasn’t Monroe’s first prison chat with a sociopath, but it was the first time a killer had called “offering his help,” writes Monroe in her new memoir, “Hearts of Darkness: Serial Killers, The Behavioral Science Unit and My Life as a Woman in the FBI” (Abrams Press), out Tuesday.

Monroe, now 69, was in the middle of investigating multiple murders in Philadelphia that may or may not have been connected.

Kemper, calling from prison in Vacaville, California, was willing to share his expertise. She agreed to hear him out, “on the theory that it takes one to know one,” Monroe writes.

She described the Philly investigation for him — what was known and unknown about the crimes — and Kemper, who decapitated most of his victims, tried to explain to Monroe the psychology of a killer.

“That’s for control, the enjoyment,” he told her. “It’s knowing that you are totally in control, and they are totally petrified of you.”

If this exchange sounds like something out of the 1991 horror classic “The Silence of the Lambs,” there’s a good reason.

Jodie Foster, who would go on to win an Oscar for her performance as FBI trainee Clarice Starling, spent weeks shadowing Monroe to prepare for the role.

“In a way, that was inevitable,” Monroe writes. “Clarice was a fictional trainee at the BSU, and I was the sole woman in the unit, the only one who could walk Jodie through our peculiar world from a woman’s point of view.”

The movie — and the 1988 novel by Thomas Harris on which it’s based — are fiction.

But the real-life inspiration for Clarice isn’t all that different from what we saw on screen.

Monroe, who investigated or consulted on more than 850 homicide cases during her 22-year-old career — including serial killers Ted Bundy, Jeffrey Dahmer and Kemper — has experienced firsthand what it’s like to try and outsmart a cold-blooded killer.

“I never felt physically afraid at all, like they were going to bust out and grab me,” Monroe told The Post about her frequent prison interviews. “What made me nervous was how smart and manipulative they could be. It was always, how can I stay one step ahead of them? Because they’ll try to trick you or get inside your head.”

Born in Long Beach, California, to a housewife and movie projectionist dad, Monroe grew up falling in love with “Dirty Harry” movies at her dad’s theater; her first ambition was to become a police officer.

After majoring in criminology at Long Beach State and a brief police career in Chino and Upland, she set her sights on joining the FBI and focusing exclusively on violent crimes.

“I had seen enough dead bodies laid out on slabs with medical examiners probing them to know that both my stomach and my psyche could handle violent death and its aftermath,” Monroe writes.

She arrived at the FBI Academy at Quantico in 1985 and in less than a year, had her badge.

After a stint in Tampa, she returned to Virginia to join the FBI’s Behavioral Science Unit, “one of the Bureau’s truly elite units,” she writes.

Monroe soon proved that she not only had the brains for the job but the stomach.

“One afternoon I might be consulting a manual on the various ways in which flesh decays,” she writes. “The next day I would be comparing decapitations with my morning coffee.”

She became exceptionally skilled in victimology, the science of reading a body for clues, and uncovering not just how someone died by why.

“Let’s say you found a woman strangled to death in her house,” Monroe told The Post. “Was it manual strangulation? Was there a cord around her neck? If her body was found dressed in a negligee and all our friends insist she was a very modest, safety conscious person, she wouldn’t have invited someone in dressed like that if she didn’t know them.”

Monroe once investigated a murder scene where the victim had been stabbed 76 times.

“And several of them were to the hilt of the knife,” she said. “That’s a cut of anger. And overkill. That was not just some random guy.”

Monroe had a special talent for finding details in a crime scene that illuminated a killer’s personality—and possibly his motivation.

“Dead and mutilated bodies are not silent,” Monroe writes. “Did the killer leave a signature that would help tie victims together? Did he sever their heads? Open up their chest cavities and examine the organs? Did he keep a particular body part or similar body parts as souvenirs of his crimes?”

It wasn’t long before Hollywood came knocking, and it wasn’t just Jodie Foster who wanted to watch and study Monroe in action.

In 1992, Demi Moore was planning to star in a film adaptation of one of author Patricia Cornwell’s bestselling crime novels and got permission from the FBI to follow Monroe for research.

But she proved to be a less-than-enthusiastic student.

“How long is this going to take?” Moore asked after being invited to sit in on a consultation about an open murder case.

“Probably five or six hours,” Monroe told her. “It’s a triple homicide.”

Moore rolled her eyes, and made it less than an hour before slipping out.

Later, when practicing at the shooting range — Moore “had little or no experience with firearms,” Monroe writes — the actress allegedly became enraged while Monroe tried to snap a few photos to memorialize the event.

“Demi was fiercely protective of her image and threatened to sue if any of the images I had just taken ever saw the light of day,” Monroe writes. “Actually, she didn’t put it quite that nicely. Miss Congeniality, Demi was not.”

The movie never got made.

Foster was much more engaged and eager to learn, even agreeing to take part in the FBI’s Yellow Brick Road obstacle course for new recruits.

The course includes a 6.1-mile run over uneven, hilly terrain that requires participants to scale rock faces, jump through fake windows and crawl under barbed wire through mud.

Although Foster wanted to sit in on an actual prison interview — a major plot point in “Silence of the Lambs” — she had to suffice with Monroe’s stories, which could be harrowing.

“You have to know, going in, that a hundred hungry male eyes are staring at you, all at the same time, boring holes in you, tearing your clothes off with their eyes,” Monroe writes of going into prison. “You have to expect hooting, whistling, lewd comments, all that, and you can’t expect the guards in most prisons to do a lot to help you.”

One of the details that Monroe shared with Foster — an incident in which a male prisoner threw a fistful of ejaculate at her as she passed in the prison hall — ended up being included in the film, which Monroe says “was almost as repulsive as it was when it happened in real life to me.”

When Monroe saw the finished movie, she was surprised at how much the filmmakers got right about her world.

Even the iconic scene in the film’s tense third act, when Clarice knocks on the door of Buffalo Bill’s home, not knowing what horrors awaited her inside, was all too familiar to Monroe.

“I refer to myself as an adrenaline junkie,” she told The Post. “I enjoyed the ‘knock-and-announce,’ as we call it. It was always stressful because you knew whatever was on the other side of the door probably wasn’t going to be good, but you did it anyway.”

Monroe is now retired and lives in Arlington, Texas, working part-time on a cyber security engagement for a large company.

The only part of “Silence of the Lambs” that truly scared her, she said, was Hannibal Lecter.

Although she never met Alfredo Ballí Treviño, the Mexican surgeon/ serial killer who inspired the character, she claims that, at the FBI, charming sociopaths like Hannibal Lecters “were our daily diet, no pun intended. We saw echoes of him constantly — through in-person interviews we conducted, by studying their victims’ remains and by poring over case studies of earlier serial killers to hone our understanding. Most of us had seen our own Hannibal Lecter face-to-face in one form or another.”

The one detail of “Silence” that still chills her blood is Hannibal’s voice.

“Anthony [Hopkins, who played Hannibal] had that flat, soft voice,” she said. “Edmund Kemper sounded just like that. He was very robotic.”

She remembers once meeting with Kemper in prison, and how, during a lunch break, she and another agent rode with him on an elevator.

Kemper looked at them and, in an atonal voice devoid of any emotion, muttered, “I could kill you both right now if I wanted to.”

It was the same voice she heard in Hannibal Lecter, and to this day it still makes the hair stand on the back of her neck. “

They don’t have feelings or emotions like the rest of us,” she said of serial killers. “So they don’t recognize that most people have some kind of inflection or intonation when they speak.”

She pauses to shake off the heebie-jeebies. “It still freaks me out.”