Vertical strips show fingerprints a polygraph test a woman's profile and a man in a long coat.

The Lie Detector Was Never Very Good at Telling the Truth

Taking a polygraph test is always stressful, and the results are often flawed. So why have police been using it for 100 years?

For months in the spring of 1921, a women’s-only private dorm at the University of California, Berkeley was rocked by a crime wave. College Hall, located on the northeastern corner of campus, where Hearst Avenue began to climb into the hills, was home to 90 young, mostly affluent women—18- and 19-year-olds, whose possessions kept disappearing.

It started small: silk undergarments, books, registered letters, items whose absence could be attributed to carelessness. The housemother was reluctant to involve the authorities, so she brought all the residents together for a meeting and demanded the thief come forward. When that didn’t work, she launched her own investigation. All she discovered was that the robberies seemed to be concentrated in one corner of the dorm.

Then, on the night of March 30, 1921, Ethel McCutcheon, a sophomore from Bakersfield, returned to her room to find her evening dresses had been removed from her closet and spread out on the bed. A textbook with $45 tucked inside had been taken, and her bureau had been ransacked. McCutcheon was not the only victim that evening. Rita Benedict, a freshman from Lodi, had more than $100 in jewelry and cash go missing. Margaret Taylor, a first-year student from San Diego, couldn’t find her diamond ring. It was worth $400 (more than $6,500 today). Taylor had no choice but to contact the police.

“I am really doing what all of the 90 girls in our dormitory didn’t want anyone to do,” she told the desk sergeant at the Berkeley Police Department. She seemed embarrassed to have to ask for help. “We do not want publicity, but this thing really can’t go on.”

Taylor might have wanted to avoid attention, but the police department was all too eager for publicity in those days. Its police chief, August Vollmer, had an unorthodox approach—and a journalist embedded in the department to tout his achievements. A gray-eyed veteran who had served in the Philippines, Vollmer was the first police chief in the country to treat crime as a problem that could be attacked with science. He hired experts in fingerprinting and handwriting analysis and put together a “morgue book” comprising images of corpses, weapons, and wrecked cars that he thought could prove useful in future forensic investigations. He also provided his officers with the latest technology, installing a rudimentary signaling system around Berkeley so they could call for backup. He was the first to equip his officers with vehicles: first bikes, then motorcycles and cars. And he slowly replaced the uneducated brutes who dominated policing with fresh-faced rookies hired from the university. The newspapers disparaged them as “college cops,” but these diligent young men, armed with degrees and committed to justice, quickly got results. Berkeley’s crime rate started to fall, even though the town’s population had almost doubled since the 1906 San Francisco earthquake and fire. As a result, Vollmer is to this day considered the father of modern policing. 

After Taylor contacted the station, Vollmer assigned the College Hall case to Jack Fisher, a seasoned veteran, and Bill Wiltberger, a college cop who had joined the force just four months earlier. While Fisher questioned the young women at the dorm, Wiltberger toured Berkeley and Oakland’s secondhand stores, used bookshops, and pawnshops in search of the missing items. Fisher found no shortage of suspects: The dorm’s residents were quick to spread rumors and fire contradictory accusations at one another.

As the investigation dragged on, the housemother began to worry that the repeated visits from the police—conspicuous in their sharp uniforms—might start to tarnish the reputation of College Hall.

At the same time, Fisher was growing impatient, so he asked Chief Vollmer to bring in John Larson, a college cop with a background in science. He thought the strange device Larson was building for the force might be able to help wrap up the case.

Larson was an awkward 29-year-old with a doctorate in physiology who had joined the police force in search of real-world experience before embarking on a career in criminology. But he was a terrible cop. He crashed cars and let suspects get away, and the stubborn obsessiveness that made him a good scientist led to several altercations with his colleagues, at least one of which culminated in a wrestling match at police HQ. 

A few weeks before the College Hall case landed at the station, Vollmer had called Larson into his office to tell him about a paper he’d just read by William Moulton Marston, a Harvard psychology student. Marston had come up with a new method for detecting lies using a person’s vital signs after he noticed that the heart rate and blood pressure of his fellow students would rise when he asked them to tell deliberate falsehoods. (Marston would go on to create Wonder Woman and her Lasso of Truth.) Vollmer wondered whether Larson might be able to refine Marston’s method—which simply used a blood pressure cuff and stopwatch—and turn it into an objective measurement whereby a suspect’s emotional responses to questions could be recorded and referred back to. 

Larson was relieved to step away from daily policing. After a few weeks of tinkering, and with the help of a lab technician at the university, he came back to Vollmer with an ugly device made of a series of rubber tubes and a roll of charcoal-blackened paper attached to a wooden board. When wrapped around a suspect’s arm and chest, the tubes would swell and contract with the motion of their heart. That movement was then transferred to two pens that scratched out a record of their emotions on the scrolling paper, white lines against black. 

Larson named his device the “cardio-pneumo-psychograph,” but of course it would go down in history as the polygraph machine—the lie detector. Soon, Larson was running tests of his invention on his colleagues, as well as experiments on undergraduates. With each examination, he sharpened his technique and became better at telling when subjects were lying. But he knew that a real-world test would be the only way to properly validate the technology. “Aside from a few experimental tests, no real cases had been run, that is, cases in which the suspect repressed the truth through fear of the consequences,” Larson wrote. Until the day Vollmer called him in.

“John, I think we’ve got a real case to work on,” said the chief, his deep voice brimming with excitement. He suggested Larson take his apparatus to the dormitory and test all 90 residents. “It’s a great opportunity to see what the machine can really do.”

This is how the seemingly trivial case of a missing ring at a college dorm became a pivotal moment in the history of the justice system—a public debut for the now infamous lie detector.

John Larson was slightly wary of his new assignment. He had been hoping for something a little more straightforward, with fewer suspects to test, for his invention’s first outing. But he knew the College Hall case would be the make-or-break test for the science of lie detection, so he approached it with care. He was, after all, a meticulous planner.

After securing permission from the housemother, he called all the women together and asked them to vote on whether they’d be willing to be tested on the new machine. They all agreed—perhaps because refusing to take part would have seemed like a clear indication of guilt.

Larson’s experimental method—largely the same as the one still used by polygraph examiners today—involved comparing the body’s response to innocuous control questions with how it reacted to questions relating to the crime or the subject being investigated.

“The questions should be simple and not too involved,” Larson wrote. Each one was designed to be answered just “yes” or “no” to minimize differences between people. This was meant to be an examination, not an interrogation—a scientific test, not a fishing expedition.

On April 19, 1921, just three weeks after the $400 ring was stolen, the machine was ready for its debut in a criminal case. To start with, 14 young women from the dorm—a mix of suspects and control subjects—were asked to come to the physiology lab at the university.

The women waited in an antechamber and were summoned into the room one by one. First up was Margaret Taylor, the owner of the missing diamond ring. She wasn’t really considered a suspect (in fact, she’d been helping Fisher with his inquiries), but it was worth ruling out the possibility that the complaint had been faked.

Larson called the 20-year-old Taylor into the lab. As she took a seat, her bright blue eyes took in the strange contraption on the table next to her. Larson took in her pretty face and the golden ringlets cascading down to her shoulders.

Fisher loomed moodily in the background. But Vollmer, standing at the back, was eager to see how the machine performed. The two watched as Larson wrapped a blood pressure cuff around Taylor’s bare arm and pumped it up until it pinched tightly against her pale skin.

Then he wound a rubber hose around her chest to measure her breathing and told her to hold still as he switched on all the instruments. The drums began to spin, and as Taylor’s breath rose and fell, the tubes around her chest swelled and shrank, translating the beating of her heart into white lines etched on the black paper. The room was silent but for the whir of the machinery and the slow scrape of the stylus.

It was an odd situation, and Larson could perhaps sense Taylor’s tension. He broke the ice, according to Reader’s Digest, with some “charming conversation.” Per this account, which was based on correspondence between Larson and the writer decades later, the detective quickly forgot the control questions he’d planned to ask, and the two began talking instead about Taylor’s favorite books and music, and her parents.

She asked about his work. He told her about his interest in fingerprinting and criminology, how he wanted to prevent crimes instead of solving them. Despite the nine-year age gap, Larson “found her intelligent and witty, as well as lovely … She told him he was wonderful to be doing so much and to be so ambitious.”

But soon he remembered that he was supposed to be conducting a police investigation. “Now,” he said, with a smile, “shall we get down to business?” Over the next six minutes or so—any longer and the blood pressure cuff started to hurt—Larson worked his way through a list of eight questions, starting with the innocuous (“Do you like college?” “Are you interested in this test?”) and progressing to the targets (“Did you steal the money?”). The drums spun, the pens scratched, and Margaret Taylor’s inner life was etched forever onto a roll of black paper. At the end of the test, Larson paused to examine the records, scanning the waving lines for swings in blood pressure and heart rate that might indicate deceit. He’d take a closer look later.

For the rest of the day, as a light drizzle slicked the paths and parks of Berkeley, Larson attached his machine to woman after woman, repeating his list of questions again and again. Then he came to Helen Graham.

Graham was slightly older than most of the other residents of College Hall. She had trained as a nurse before enrolling at Berkeley. In her yearbook photo, she’s turned away from the camera, looking back at the lens with a smirk, her dark hair cut into a flapper bob. Graham’s roommates were suspicious of her clothing and fine jewelry—which, one of them told Detective Fisher, seemed out of step with her modest Kansas family. “She is of the highly nervous type and has been suspected of being a hophead,” Fisher reported, using slang for an addict or drinker. She was one of his main suspects.

Graham showed no emotion as Larson worked his way through the list of questions—until he got to ones about the missing money and jewelry. “Did you take Miss Taylor’s ring?” Larson asked. After she answered a quick “no,” he glanced at the chart.

“The test shows you stole it,” he said flatly.

Graham seemed to stop breathing. She glared at Larson. “I think all these questions are an insult,” she said. “Just because I’m excited and mad at being asked all these questions, the needle jumps, and you think I’m lying.” Her eyes burned with rage. She started shouting. “It’s the third degree, that’s what it is. The needle shoots up and I’m a liar!”

“No one has said you are a liar,” Larson said in a low voice, trying to defuse the situation.

“You’re trying to make me out a thief—that’s what you’re doing. I won’t stand for it.”

As Larson leaned forward to take Graham’s blood pressure reading, she burst out of the chair and charged over to the spinning drums of the polygraph, which were still tracing her body’s increasingly violent movements. Larson and Fisher jumped up and had to hold her back from destroying the equipment as she railed against the men and their machine. Her blood pressure and heart rate were still going up as she tore the cuff off her arm.

“Are you through with this crazy stunt?” she spat.

“Yes, we’re through,” Larson replied.

But Graham was already charging out of the room. Outside, she told one of the other women she had wanted to tear up the charts, and that if she hadn’t been restrained by the equipment she would have “smashed Officer Fisher in the face.”

Inside, Larson and Vollmer exchanged glances. “That isn’t the girl the housemother suspected, but I’m betting she’s the one,” Larson said.

“I don’t think there is any doubt of it, but we have no confession,” Vollmer said. “I’ll have the girl watched. Maybe we’ll get some real evidence.”

Overnight, Larson found out more about Graham from the other women in the dorm. They told Larson and Fisher that Graham had been entangled in several passionate affairs and that she’d once induced an abortion by taking the anti-malaria drug quinine—hardly relevant to the case, but a cause for suspicion by the attitudes of the time.

The next day, Graham turned up at the police department, demanding to speak to Larson and asking to see the chart. Larson and Fisher then interrogated her for 12 hours while she continued to maintain her innocence. Eventually, though, she broke into “an attack of sobbing,” and said that yes, it was possible she might have taken the items in her sleep.

Graham then offered to replace the missing ring and the money if it meant the police would stop investigating her. Larson, always inclined to pursue the truth at any cost, told her that if she was genuinely innocent she shouldn’t make that offer. Fisher, by contrast, told her if she was guilty, she’d be prosecuted whether she replaced the items or not.

They sent Graham home, but she turned up at the police station every day that week, begging to be seen. It was only when she threatened to hurt herself that Larson relented. “During the interview she threatened suicide unless the case was cleared up at once,” Larson wrote, adding that Graham displayed a “very unstable personality.”

But the police still didn’t have a clear confession. Larson arranged another interrogation, and on April 30, at the Berkeley Police Department in the basement of City Hall, he and Fisher supplemented the lie detector with a more traditional interview technique. “Officer Fisher played the role of ‘hard-boiled cop’ with his usual adroitness, and I was her friend,” Larson remembered.

Over the course of the interview, the policemen learned that Graham’s life wasn’t simple, but was, in fact, traumatic: She’d been sexually abused as a child and felt intensely guilty about an affair she’d had with a married medical student before coming to California. After several hours, Fisher rose suddenly to his feet, threatened Graham with the prospect of imprisonment in San Quentin (which still housed women until 1933), and then stormed out of the room. 

While Fisher was gone, Graham finally admitted to taking the money and the ring, as well as some items of clothing. In exchange for the confession, she wanted guaranteed immunity from prosecution and to avoid being named publicly.

When Fisher returned, Graham signed a written confession. The lie detector had solved its first case. Vollmer was delighted. He was eager to roll it out on more hardened criminals. “The problem of lying, the bane of the human race for hundreds of years, could now be dealt with,” is how one biographer summarized Vollmer’s thoughts at the time. 

But Graham was devastated. She dropped out of university and moved out of College Hall into a hotel while she got ready to go home to her parents’ farm. When she got back to Kansas, she wrote Larson a letter recanting her statement, “saying that she had been told that she was a fool for confessing,” he recalled. “She even denied her guilt and intimated that she had been tricked into a confession.”

As Larson worked on more cases that year—many involving sororities and college students—he started to realize that the inner rumblings of the body were more complicated than they seemed; that a change in blood pressure was not necessarily a telltale sign of deceit. As we know well now, a lie detector test is inherently stressful, and being asked about a theft or a murder weapon can cause an emotional response whether a person is guilty or not. Over the past 100 years, those flaws have proliferated as the use of the machine has spread across the world. In fact, despite being repeatedly debunked by numerous scientific studies, polygraph tests are still widely used to screen government employees and to pressure suspects to confess. Test results are hugely biased by who is running the test, and who is being tested.

The College Hall investigation was the start of a pattern of misuse and power imbalance that has continued for more than a century, altering the justice system and our relationship with the truth in ways that are still being felt today. New forms of lie detection are coming to the fore, powered by brain scans and artificial intelligence: In India, EEG scanning was used to sentence a woman to life in prison (this was overturned on appeal); in the European Union and the United States, AI-based lie detectors are being tested for use at border crossings. Despite the biases baked into these new technologies, their inventors still say they’re impartial, objective, and infallible—the same claim John Larson and his colleagues once made about the polygraph machine.

Larson often found himself investigating people who, like Helen Graham, felt desperately guilty—just not of the crime he was investigating. Over the next few years, he “unmasked midnight poker games, petty shoplifters, pregnancies, and attempted abortions, often without solving the original crime itself,” writes Ken Alder in The Lie Detectors, which gives a thorough account of the sorority case. Ultimately, Larson had mixed feelings about the College Hill case. Yes, Graham had eventually confessed, but only after a month of being ostracized by her peers and hounded by the police. Larson began to sympathize with the young woman. “I am very sorry that you have been feeling blue and wish that I could do something to make you feel better,” he wrote to her in May 1921.

As Larson’s work with the lie detector progressed, he tried to rule out external factors that might influence or even throw off the tests. He started to suspect that in some cases it might be the questioner and not the questions that elicited an emotional response.

To test this theory, he asked Margaret Taylor to come back to the lab for a follow-up experiment. “I thought you’d told me that I had passed,” she said when she arrived. “Now what’s wrong?”

“Nothing,” he said. “But I’ve got a new question here that’s not on the list I first prepared.”

Seating Taylor in front of the lie detector again, he went through the preamble of the experiment. Then he asked her to lie to him on purpose, and he tried to tell when she was doing it. Their rapport was light, easy.

Before Larson let Taylor go, there was one more thing he wanted to know. “There’s a special question that I want you to be sure to answer truthfully,” he said, according to Reader’s Digest. (In a letter to Marston written years later, Larson dismissed this aspect of the account as “pure hooey,” although he did not seek any corrections to the piece when he corresponded with its author before publication.)

His voice had acquired a strange quality. “It’s here on the list. Go ahead, please.” Taylor took the piece of paper from the detective. Her eyes widened as she read the four words scribbled in Larson’s spidery handwriting. She could feel the blood rushing to her face.

Larson had discovered during his experiments that short, basic queries were the best questions to ask. The one he had written down for Taylor could not have been more simple: “Do you love me?”

She quickly said no, but Larson didn’t need a machine to tell that she was lying. For a moment, she looked across at the rookie detective, his eyes fixed on hers. Then her gaze flicked over to the rolling drums of the apparatus and the black paper that had opened a window to her heart. According to The San Francisco Examiner, “the wings of the ‘lie detector’ trembled, fluttered, waved a frantic SOS.” That story was published 16 months later, on the day of Larson and Taylor’s wedding. 

In time, Larson would remember this moment fondly. He marveled at the possibilities of the device—not only could it solve crimes, but it could shine a light on the deepest secrets of the soul, uncover hidden longings and dark impulses. But while his romance with Taylor blossomed, his relationship with the machine that brought them together quickly turned sour.

Larson had hoped the polygraph would predict crimes before they happened and bring science and reason to the brutal business of justice. Instead, he came to see the lie detector as an experiment that had spun out of control—a “Frankenstein’s monster” that he had inadvertently unleashed.

CORRECTION 3/3/23 3:30 PM ET: A previous version of this story referred to Helen Graham as “Heather" Graham on the second reference. It has since been updated to correct the error. 

Excerpted from Tremors in the Blood: Murder, Obsession, and the Birth of the Lie Detector by Amit Katwala. Copyright © 2023 Amit Katwala. Published in the United States by Crooked Lane Books, an imprint of The Quick Brown Fox & Company LLC. First published in the UK by Mudlark. Reproduced by arrangement with the publisher. All rights reserved.

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