Catching a KiIler Doctor
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On the 21st of August, 1974, Elaine Oswald made a visit to the doctor's office in a small town not far from Manchester in the north of England. Oswald had a slight pain in her side, but she was hoping to go into work later that day. Oswald had never met this particular doctor before, and he was only a few years older than she was. She was only 25. He had spectacles and the kind of big brown beard that was fashionable at the time.

The doctor couldn't have been friendlier or more accommodating. He sat beside her, not over on the other side of a big desk, and he told her she might have kidney stones. He prescribed some strong painkillers and suggested she go home and rest. Leave your door unlocked, he said. I'll come round after my morning clinic has finished and do a blood test. Later that day, he stopped by.

His wife and son were in the car outside, he said. Just a quick jab with a needle to draw the blood and he'd be on his way. The needle slid into her arm. The next thing Elaine Oswald remembers was waking up on the floor with a doctor and two paramedics trying to revive her. She was rushed to hospital, where the staff, she recalled, treated her like the scum of the earth. They assumed she'd overdosed on those painkillers.

The young doctor was much kinder. "She must have had an allergic reaction," he said. "Thank goodness he'd been there to administer the kiss of life." He promised to write up the case for a medical journal. She was grateful, of course. Who wouldn't be? When she was discharged from hospital, the kind doctor even invited her and her husband for dinner. It was a pleasant evening. He gave her a medic alert bracelet so that no future clinician would accidentally prescribe similar drugs.

she'd go on to have two children, toughing it out through the agonies of labour without pain relief. Elaine Oswald eventually moved to America, became a professor of English, and for the next 25 years assumed that the kind doctor, a man called Harold Shipman, had saved her life. She couldn't have been more wrong. I'm Tim Harford, and you're listening to Cautionary Tales. CAUTIONARY TALES

It took 25 years for the world to realise that Harold Shipman was not the kindly doctor who believed in his patients while others treated them badly. Not the bold lifesaver who'd leap to administer the kiss of life. Not the caring man who'd go the extra mile to visit his patients at home rather than drag them into the clinic. No, he was not.

Harold Shipman was a murderer. And not just any murderer. In sheer numerical terms, he was the worst serial killer in history. There are plenty of notorious killers. The charming Ted Bundy. John Wayne Gacy, the killer clown. The son of Sam, David Berkovitz. But while Bundy, Gacy and Berkovitz, between them, killed more than 70 people, Shipman alone...

killed more than 200. Often his victims would be people living by themselves, elderly but in perfectly fine health. Shipman would come round, inject them with an overdose of morphine, just as he'd injected young Elaine Oswald, and then sign a death certificate saying that they had died of old age. When I began researching this cautionary tale, I knew that Shipman was a terrible man. I didn't understand quite how terrible.

I vaguely had in mind a doctor who started down this path by easing the deaths of patients who were in pain and terminally ill, and then got carried away. But the truth is so much more horrible than that. Shipman would kill healthy people, then to explain their deaths, he'd say they'd been drug addicts, he'd retrospectively tamper with their medical records, and leave the bereaved families bewildered.

More than once, he killed someone in his clinic, then would claim they'd died of heart failure. He may have killed a severely disabled four-year-old girl. When one middle-aged man, Jim King, was misdiagnosed with cancer, Shipman intercepted the letter from the hospital with the good news that he was cancer-free after all. Shipman supplied Jim with morphine, got him hooked.

and watched as Jim lost his job and pawned his possessions. Meanwhile, Shipman skimmed off some of that morphine and used it to murder Jim King's own father. Why did he do it? Plenty of people have speculated, but nobody knows. One doctor, an expert witness at Shipman's trial, mused that while some doctors would relax from the stresses of the profession by playing a round of golf...

Shipman seemed to relax by murdering his patients. Shipman, who killed himself in prison, never offered an admission of guilt, let alone an explanation. But this cautionary tale isn't going to pick apart Harold Shipman's psychology. No, this tale, like all our tales, is about the lessons we can learn.

Here, the lesson is that Harold Shipman could have been caught much earlier. Maybe not as early as 1974 when he injected the young Elaine Oswald with morphine, perhaps intending to kill her and perhaps with some other wickedness in mind. But he could have been caught early enough to have saved more than a hundred lives. In the early hours of July 29th 1976, in the Bronx, New York,

Jodie Valenti and her friend Donna Lauria sat in their Oldsmobile chatting. They were just outside Donna's home. Donna's parents were inside. Both of them were in medical training. Jodie to be a nurse, Donna to be a medic. But Donna would never get the chance to finish her studies. Jodie Valenti was a young woman like Elaine Oswald. But her brush with death at the hands of a serial killer was a complete contrast with Elaine's.

As Jodie and Donna were talking, a man walked up, pulled out a pistol and shot them both. Donna Lauria died instantly. Jodie Valenti took a bullet in her leg and she survived. She was, of course, traumatised and she obviously understood quite how close she'd come to death. Unlike Elaine Oswald, she didn't spend the next 25 years believing that her attacker was a hero who'd saved her life.

the NYPD had a clearly defined problem. Someone, calling himself the Son of Sam, was wandering around New York City, shooting young people, leaving some dead, some disabled, and the whole community in a panic. He had to be found. And eventually, in August the following year, he was found. In the case of Harold Chipman, the Greater Manchester Police faced a radically different problem. The problem, in fact...

was to realise that there was a problem. Because the police had no idea that people were being murdered. People were dying, yes, but according to their doctor, they were dying of natural causes. The deaths were a surprise to friends and family. Most of the time, the victims weren't seriously ill, just old and alone. In the morning, they would be pottering around, catching the bus or dropping in on a neighbour, in good shape and fine spirits.

And in the afternoon, dear, kind Dr Shipman would come by on a routine visit and, according to Dr Shipman, well, he'd find them dead. Dead of old age, he would often write on the death certificate, even though doctors would normally be more specific. And while their friends and relatives were shocked, they weren't shocked enough to call the police.

As far as the police were concerned then, there was nothing to investigate. Sarah Marsland died on the 7th of August 1978 at her home in Hyde, a small town near Manchester. Harold Shipman was her doctor. He had moved to Hyde in 1977. By coincidence, that was about the time my own family moved to the area. I was four years old. I'm so glad I never came any closer to his orbit.

We can't be absolutely sure that Sarah was one of Shipman's victims because nobody even suspected that a crime had been committed until more than two decades after she'd died. But the circumstantial evidence is this. Although Sarah Marsland seems to have had no particular health complaint, Harold Shipman came to see her uninvited and unannounced.

While he was there, she died. It wasn't unusual for Shipman to visit patients for no particular reason. He did it all the time and they loved him for it. A good, old-fashioned, hard-working doctor, they said. Someone with all the time in the world for his patients. But even so, it is a striking coincidence that someone would drop dead just when a doctor happened to be popping in for a friendly visit.

One physician later testified that this was the sort of coincidence that might be a once-in-a-lifetime experience for a family doctor, but for Harold Shipman, it seemed to happen every few weeks. Nevertheless, nobody raised the alarm about Sarah Marsland at the time. And why would they raise the alarm? She was in her 80s, and her own doctor had declared that she'd died of coronary thrombosis. The situation didn't seem out of the ordinary.

A few years before Sarah Marsland's death, two psychologists, Daniel Kahneman and Amos Tversky, began investigating patterns in the way we make judgments. One pattern that they discovered helps to explain why nobody suspected Dr. Shipman for a very long time. That pattern is known as the representativeness heuristic pattern.

A habit of mind that leads us to sort a situation into strange or unremarkable, depending not on the true likelihood, but whether it matches our existing mental groupings. For an example of the representativeness heuristic, consider the following description of a person. He's called Jeff. Jeff is 40 and very good looking. He works out, practices yoga and is a vegetarian.

When he was a teenager, Jeff was a movie buff, and he also took the lead role in the school play. He's always been extroverted, he's already gone through two divorces, and his current girlfriend is 15 years younger than him. Which of the following do you think is more probable? Jeff is now a Hollywood movie star, or Jeff is now an accountant? Intuitively, Jeff sounds like a movie star, but that's not right.

There are just a few dozen genuine movie stars in Hollywood, while there are well over a million accountants in the United States. Many thousands of them will, like Jeff, be good-looking, twice-divorced vegetarians with a background in amateur dramatics. The representativeness heuristic is a quick and easy way for our subconscious mind to make decisions. We use it all the time, without knowing, and it often works. But it can lead us astray.

It led the community of Hyde astray too, in a subtly different way. Harold Chipman didn't repeat his early mistake of drugging a 25-year-old Elaine Oswald. He began to target much older people, people like the widow Sarah Marsland.

Although Sarah was in decent health, she fits the mental template of someone who would die from natural causes. My point is not that when an elderly person dies we should assume it was murder, not even when the elderly person dies just as her doctor happens to call past unannounced.

No, my point is that when something fits neatly into our mental story, we don't ask questions. We don't start to weigh up the probabilities of murder versus natural causes. If we did, we'd simply ask for an autopsy, wouldn't we? But we don't. And we don't, because what we see fits naturally into the story we expect.

So the fundamental problem was, not only did people not realise that Shipman was a murderer, they didn't even realise that there were any murders taking place. The representativeness heuristic reassured them, nothing strange is happening. Move on, there's nothing to see. Cautionary Tales. We'll be right back.

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Shipman murdered people with lethal doses of morphine, which left no obvious trace unless there was an autopsy. But why would there be one? The representativeness heuristic tells us nothing strange has happened. Shipman would sign the death certificate himself to certify death from old age or heart failure. No need to call the ambulance, he'd say. Too late. No need to call the police. He could deal with the necessary paperwork himself.

Again and again, Harold Shipman murdered people in their own homes. And again and again, the friends and the family of the victims did not realise that a crime had been committed. Indeed, many people were grateful to Shipman, glad that in their final hours, the patients had had the close attention of the doctor they adored.

Not everyone felt that way. In 1994, for example, Alice Kitchen died suddenly at the age of 70, a few hours after seeing her son and appearing to be in good health. Dr Shipman told her family that he'd called in to visit her, that she'd clearly suffered a stroke, but that she'd refused to go to hospital as he'd suggested. It was a cruel lie, and an arrogant one. Alice Kitchen's family decided against making a formal complaint,

But they were angry. They thought Shipman was guilty of negligence. In their book about Shipman's crimes, Prescription for Murder, the journalists Brian Whittle and Gene Ritchie muse on the nature of the murders and the people who died.

Their ages meant that the deaths would not make any statistician raise an eyebrow. 70, 74, 69, 83, all within the range that death comes. The deaths would not make any statistician raise an eyebrow. It seems an uncontroversial phrase. After all, elderly people die all the time, don't they? But it's quite wrong. The representativeness heuristic is soothing us into keeping our eyebrows unraised.

But statisticians don't use the representativeness heuristic. They use the data. And any statistician given a look at the statistics behind Harold Shipman's clinical practice would have raised more than an eyebrow. They would have raised the alarm. Professor Sir David Spiegelhalter is one of the UK's foremost statisticians. He's a brilliant communicator of statistical ideas and the author of a great book, The Art of Statistics.

David was asked to provide advice to the commission set up after Shipman was jailed, invited to answer the obvious question, could Shipman have been stopped sooner? And to David Spiegelhalter and the other statisticians considering the problem, that answer was, of course he could have been stopped. All you had to do was look at the numbers in the right way.

Interrogating statistics to set our alarm bells ringing was an idea developed by the Allies during the Second World War. At Columbia University, New York, the great Hungarian mathematician Abraham Wald was working on military mathematics and he developed what he called sequential testing. Meanwhile, a young mathematician named George Barnard was working in London for the fabulously named Ministry of Supply.

Because of the wartime secrecy, Wald and Barnard weren't aware of each other's work, but they were working on the same basic problem, which is this. Let's say you have a process which produces a random output, say rolling a die. You roll a 1, then a 4, then another 1, a 2, 1, 5, 3, 1, 6. On you go.

You can keep rolling as many times as you like. So at what point do you say, "Hey, there's something strange about this die. I'm rolling too many 1s." You can use the same idea to check products coming off the production line. You don't want to stop the conveyor belt just because of a single faulty product, but neither do you want to keep the production line rolling forever if there is a steady stream of problems.

Wald and Barnard would have been particularly focused on the manufacture of ammunition and other armaments. But the maths can be applied more widely. Sample some cookies to check whether they have enough chocolate chips in them. Or check the strength of condoms by inflating them to see if they stand up to the strain. Any product will have a failure rate. But at what point do you say, hang on a minute, something's wrong.

David Spiegelhalter and his colleagues told the Shipman Inquiry that looking for suspicious patterns in medical records was fundamentally similar to looking for suspicious patterns in dice rolls, or cookies, or condoms. You might want to make some adjustments for the mix of cases. A doctor serving a retirement community is going to have a very different case mix from a doctor working on a military base, but the principle is the same.

track deaths over time among each doctor's patients, just as you might track faulty cookies or faulty condoms. Spiegelhalter and his colleagues concluded that the kind of analysis developed by Wald and by Barnard could have flagged Harold Shipman for close attention as early as 1984, 14 years before he was eventually arrested. More than 100 murders could have been prevented.

And that's just one statistical method. Other ways to slice the data also raise questions. For example, there were a couple of years in which Shipman went quiet, perhaps fearing that other doctors in the clinic would notice what was happening. When he left to set up shop as a lone practitioner, the murders began again. With hindsight, all this is clear in the data.

Even clearer is the fact that so many of Shipman's patients died in the early afternoon, a convenient time for Shipman's home visits. The pattern, says Professor Spiegelhalter, requires no subtle statistical analysis. It is what statisticians call interocular. Draw a graph and it hits you between the eyes.

Not all statistical anomalies result from foul play, of course. David Spiegelhalter told me about one doctor who had a truly extraordinary number of deaths on his watch, even more than Harold Shipman, but there was an innocent explanation.

While Shipman's patients had often died suddenly, this doctor had been treating terminally ill patients. He'd gone to great lengths to ensure they were able to die at home rather than spending their final hours or days in hospital. As a result, the doctor ended up signing a large number of death certificates. But statistical analysis isn't designed to prove guilt. It's designed to focus attention.

Close inspection of this doctor's work revealed a person who upheld the highest standards of the medical profession. Close inspection of Harold Shipman's practice would have revealed the appalling truth. A forensic analysis of his medical record-keeping, for example, would have shown him backdating entries to invent medical problems after the fact. And a single autopsy of one of the patients would have revealed the lethal doses of morphine.

all it would have taken was someone to pay attention. And a simple analysis of the numbers would have shown them which doctor to pay attention to. But given just how simple this statistical exercise would have been, given how many lives it would have saved, and given the fact that we didn't actually do it, I have a question. What else are we missing? Cautionary Tales will return in a minute.

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The health authorities in the UK believe they now have statistical alarm bells that would ring if another Harold Shipman comes along. But what other stories are hiding in plain sight?

In 2014, Anne Case and Angus Deaton were spending the summer together in a cabin in Montana. Case and Deaton are married, both are respected economists, and they had both become deeply interested in the growing problem of suicide among middle-aged white Americans. To put that problem into context, they decided to compare suicide to the more traditional forms of death, such as heart disease and cancer.

We went to the Centers for Disease Control, downloaded the numbers, and made the calculations. They write in their new book, Deaths of Despair and the Future of Capitalism. To our astonishment, it was not only suicide that was rising among middle-aged whites. It was all deaths. Not by much. But death rates are supposed to fall year on year. So even a pause was news, let alone an increase.

We thought we must have hit a wrong key. Constantly falling death rates were one of the best and best established features of the 20th century. The finding was right there in the data, but nobody, it seems, had thought to look. We thought we must be wrong because someone would know about it. But they weren't wrong. They were just ignored.

The New England Journal of Medicine didn't want to publish the results. The Journal of the American Medical Association rejected us so quickly. We thought it was an auto-reply because we'd used the wrong email address. Case and Deaton broadened and deepened their scrutiny of the numbers. Suicide was up.

So was chronic liver disease, a sign of alcoholism. Even more dramatically, deaths from poisoning were up. Poisoning sounds melodramatic, like the cause of death in an Agatha Christie story, but it usually means a fatal overdose of alcohol or drugs, often opioids such as morphine or fentanyl.

Once a rare problem, drug overdoses have overtaken lung cancer as a cause of death for 45- to 54-year-old white Americans. And it all happened so quickly, from barely being an issue in the late 1990s to making a major dent in the mortality data just 15 years later. It is an ironic reversal of Harold Shipman's murderous career.

Shipmen killed vulnerable people with opioid overdoses. In the US, doctors have simply been supplying ever more powerful opioids to vulnerable people. Misery, pain or sheer accident have done the rest. Put these three causes of death together, suicide, accidental overdoses and liver disease, and you have a category that Case and Deaton named...

The toll dwarfs anything that one murderer could achieve. Case and Deaton found there were 158,000 deaths of despair in 2017. That is a similar scale to the first wave of COVID-19 deaths in the US. It was a catastrophe. And it was a catastrophe that should have been plainly visible in the statistics. Yet, somehow, nobody had taken the effort to look.

On the 24th of June 1998, Kathleen Grundy, the former mayoress of Hyde, died, suddenly, at the age of 81.

It was a surprise. She'd been fit and socially active. On the same day, a will arrived at a firm of local attorneys with a covering letter. The will purported to be that of Kathleen Grundy. It declared her intention to leave her house to her dear family doctor, Harold Shipman.

But the attorney had never had any dealings with Kathleen Grundy, and the signatures looked odd. A few days later, a mysterious letter from someone called Smith told the attorney that Mrs Grundy had died. Puzzled, the attorney contacted Kathleen Grundy's daughter, who was an attorney herself and well-versed in the ins and outs of making a will.

Already stunned by her mother's death, she was even more astonished to find herself and her children abruptly disinherited. There had been no family argument, no sign that a change in the will was imminent, and the new will was odd.

Why send it to an unknown firm of attorneys? Why was it riddled with typos when her mother was a trained typist? And why did it show no knowledge of the fact that Kathleen Grundy owned a second house in Hyde and a holiday cottage too? Kathleen Grundy's daughter called the police.

It didn't take long for the police to discover that the will was a forgery, that the cover letter had been typed on Harold Shipman's typewriter, and that Mrs Grundy's medical records had been altered after her death. If Shipman hadn't made such crass misjudgments, who knows, he might never have been caught. As it was, Harold Shipman was arrested.

Faced with the need to conduct autopsy examinations, the police began the terrible task of digging up the bodies all over the town of Hyde. The slow process of uncovering Shipman's awful crimes had begun. In the aftermath, some local people blamed themselves for not having spoken up sooner.

John Shaw, the gentle taxi driver who spent his days driving elderly ladies around, knew them well enough to attend funerals when they passed away. But there were simply too many funerals. Shaw told the journalists Brian Whittle and Jean Ritchie, I noticed that all those who were dying went to the same doctor, Dr Shipman. Eventually, John Shaw went to the police to discover that they were already investigating the death of Kathleen Grundy.

Could he have spoken up earlier? Perhaps. A year or two? But the police admitted that he might well have been ignored if he had. After all, he was just a taxi driver, and Harold Shipman was a respected doctor. Other people had also been growing concerned. There was Debbie Massey, a funeral director, who was responsible for burying or cremating many of Shipman's victims.

There was Linda Reynolds, another local doctor. Massey and Reynolds raised the alarm in March of 1998. Perhaps they could have spoken up in February or January. Perhaps the police could have been more vigorous in responding. But it's important to recognise we're talking about a matter of weeks or months at best. If instead we had collected the simplest of data sets, if we had run the most basic analysis of that data...

We would never have needed to depend on people risking the scorn of the police and the enmity of Harold Shipman to stop him. The statisticians, with their production line mathematics designed to inspect condoms and chocolate chip cookies, might have stopped his murder spree more than a decade earlier. Essential sources on Shipman's crimes are The Shipman Inquiry and Brian Whittle and Jean Rich's book Prescription for Murder.

David Spiegelhalter's excellent book, The Art of Statistics, covers the Shipman case. And my own book, The Data Detective, makes a plea for taking the numbers seriously. Other sources are at timharford.com. Cautionary Tales is written by me, Tim Harford, with Andrew Wright. It's produced by Ryan Dilley and Marilyn Rust. The sound design and original music is the work of Pascal Wise. Julia Barton edited the scripts.

Starring in this series of cautionary tales are Helena Bonham Carter and Geoffrey Wright, alongside Nizar Eldorazi, Ed Gohan, Melanie Gutteridge, Rachel Hanshaw, Coben Holbrook-Smith, Greg Lockett, Masaya Munro and Rufus Wright.

This show wouldn't have been possible without the work of Mia LaBelle, Jacob Weisberg, Heather Fane, John Schnarz, Carly Migliori, Eric Sandler, Emily Rostick, Maggie Taylor, Aniela Lacan, and Maya Koenig. Cautionary Tales is a production of Pushkin Industries. If you like the show, please remember to rate, share, and review.

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