Casefile True Crime - Casefile Extra: Chad Shelton & Duane Johnson

Episode Date: October 24, 2026

*** Content Warning: Crimes against children, animal cruelty, suicide ***In September 1978, 11-month-old Chad Shelton is admitted to a Nebraska hospital with suspected food poisoning. Doctors are baffled when his symptoms take a terrifying turn, and two days later, he dies. Within hours, in another part of the city, a healthy 24-year-old man collapses with the very same symptoms.As the death count rises, health officials scramble to contain the outbreak, and the city of Omaha braces for an epidemic. Then a nurse makes a chance discovery that turns a medical mystery into something far more sinister.Casefile Extra features bonus episodes exploring compelling cases, stories and topics beyond our regular weekly releases.---Narration – Anonymous HostResearch & writing – Jessica LarsenProduction & music – Mike MigasAudio editing – Anthony TelferSign up for Casefile Premium:Apple PremiumSpotify PremiumPatreonFor all credits and sources, please visit https://casefilepodcast.com/casefile-extra-chad-shelton-duane-johnson Hosted on Acast. See acast.com/privacy for more information.

For early access and ad-free episodes, check out our Patreon, Apple Premium and Spotify subscription memberships. Our episodes deal with serious and often distressing incidents. If you feel at any time you need support, please contact your local crisis centre. For suggested phone numbers for confidential support and for a more detailed list of content warnings, please see the show notes for this episode on your app or on our website. Today's episode involves crimes against children and won't be suitable for all listeners. Sunday, September 10, 1978 had been a long day for Omaha-Nabrasco couple, Sally and Bruce Shelton.

They'd been out since the morning with their 11-month-old son, Chad, shopping for furniture before visiting some relatives and then attending a birthday party. By dinner time, they were exhausted. On their way home, they stopped by a man. Mexican restaurant and ordered takeout. By the time they were back in the car, Sally began to feel nauseous. Once they arrived home, she vomited. Given that it had been an unusually hot day and she'd always had a sensitive stomach, Sally brushed it off and sat down with her family to eat dinner in front of the television. While they waited for 60 minutes to start,

Sally fed Chad mouthfuls of mince from her taco before taking a bite her son. The moment the food touched her mouth, she noticed it tasted strange. Bruce thought his taco tasted odd too. Not wanting to risk getting food poisoning, they threw the takeout in the bin. Shortly afterwards, Chad began vomiting violently. Sally had never seen her baby so sick. His whole body shook with the effort and he barely finished one bout of vomiting before another would starve. Sally and Bruce did what they could to comfort their son, but the vomiting didn't let up.

Within a few hours, they both became violently ill as well. The vomiting was so intense they could barely stand up. But as bad as Sally and Bruce felt, it was their infant's son they were most worried about. To them, it didn't seem like the normal vomiting of a child who'd eaten something bad. By 11 p.m., they were so concerned that between their own waves of nausea, they phoned their family doctor at his home. After hearing Chad's symptoms, the doctor reassured them. It sounded like a simple case of food poisoning.

By the morning of Tuesday, September 12, Chad Shelton had been vomiting for 36 hours and seemed to be getting worse. With Sally still too sick to get out of bed, Bruce Shelton drove Chad to the emergency room at the Emanuel Medical Center in North Omaha. He described Chad's symptoms to the doctor, explaining that he and his wife had been sick too, although not as bad as their son. The doctor noted that other than the vomiting, Chad was an alert and responsive baby and his vital signs were all good. His symptoms were consistent with gastroenteritis, also known as stomach flu, a common virus

that usually resolves on its own in a few days. While the stomach flu typically doesn't require hospitalisation, Chad was admitted for fluids and observation as a precaution. But as the day wore on, staff noted that Chad was developing jaundice, a yellowing of the skin that can signify liver problems. He was also increasingly listless and irritable. Then, at around 3am,

Chad's skin started turning purple and strange marks that looked like bruises began appearing all over his body. The nurses on night shift had never seen anything like it. By the time the sun was coming up the next morning, they were so concerned that they rang the head nurse at home. Nurse Linda Rummel was asleep in bed, but when she heard about Chad's condition, she raced back to the hospital. In all her years supervising the children's ward, Rummel had never had a child under the age of 10 die, and she wasn't about to let it happen now. But when she saw how much Chad's colour had changed overnight and how floppy and lethargic he'd become, she sounded the alarm.

The doctors who rushed to help the 11-month-old were confused by what they saw. It was obvious this wasn't a simple case of food poisoning or stuble. stomach flu, yet Chad's symptoms didn't seem to fit with any other illness either. Tests revealed that Chad's liver was failing and his platelets, the cells responsible for helping blood clot, had dropped significantly. This explained the strange marks that kept appearing on Chad's body. They weren't bruises at all, but areas where he'd started bleeding underneath his own skin. The doctor's best guess was that Chad was suffering. from RISE syndrome, a rare brain disease that impacts children, or perhaps a type of leukemia.

But neither diagnosis fit completely, and they didn't explain why a previously healthy baby would experience such a rapid decline. With the staff had a manual reaching the limits of their expertise, the decision was made to transfer Chad to the Children's Memorial Hospital in central Omaha, where he could receive specialised care. By the time he arrived at their pediatric intensive care unit, Chad was in a coma and suffering from massive internal and external bleeds. For the next 18 hours, Sally and Bruce Shelton, still sick themselves, watched as doctors frantically tried to save their son.

Nobody could tell them what was wrong with their only child or why he kept getting worse. Chad was put on a respirator, but soon began bleeding into the tube in his life. lungs. In fact, it seemed like he was bleeding from everywhere. No matter what they tried, the doctors couldn't keep up. Finally, at 4.30 a.m. on Thursday, September 14, 3 days before what would have been his first birthday, Chad Shelton was pronounced dead. Later that same day, a few miles across the city, 24-year-old Dwayne Johnson walked into a doctor's office and collapse. The father of two had always been healthy and rarely got sick, but four days earlier on Sunday, September 10,

he'd suddenly started vomiting. At first, Dwayne thought he'd just had the flu, but on Wednesday morning, he woke up to find he was bleeding from his gums, nose, and the whites of his eyes. His wife, Sandra, took him to the doctor, who assessed it as a routine nosebleed, Assured there was nothing to worry about, the couple returned home.

But a few hours later, Dwayne sneezed and his nose started bleeding again. There was so much blood that it covered his shoes and the carpet. Convinced this wasn't a normal nose bleed, Dwayne and Sandra headed to the emergency room at a manual medical center, where the same doctor packed his nose and sent him home. By Thursday morning, Dwayne could barely walk. Concerned that their family doctor wasn't taking Dwayne's condition seriously, they decided to try another clinic. While in the waiting room, blood began pouring from Dwayne's nose again, and he slumped to the floor. An ambulance was called, but by the time they arrived at the clinic, Dwayne Johnson was already in a coma.

As doctors tried to stabilize Dwayne, his wife Sandra became visibly upset. She told staff she had a two-year-old daughter named Sherry at home who had also been sick since Sunday. While the toddler seemed to be managing okay, Sandra was scared the same thing that happened to Dwayne could happen to Sherry too. She told the staff that it had been a nightmare week. On top of everything else, her baby never. had died that morning from an unexplained illness.

Sandra said she'd barely had time to take in the news when Dwayne collapsed. To the staff listening, it sounded like the family had had an awful run of bad luck. Later that afternoon, Nurse Linda Rommel was chatting with a colleague who happened to mention the awful case her team were working on. A young father was dying and no one knew why. To make things even sadder, the man had a baby nephew who'd just died that morning at the children's hospital. Linda Rummel, who had lost a young patient that morning, stopped what she was doing. She asked what the man's symptoms were, and her colleague told her, severe vomiting, coma, low platelets and uncontrollable bleeding.

The hairs on Rummel's neck went up. The list was eerily familiar. One phone call later, and it was confirmed, the man's nephew was 11-month-old Chad Shelton. The connection between the two patients changed the situation entirely. Doctors were no longer dealing with two sad, yet isolated cases, but a potential public health emergency. They still didn't know what had killed Chad Shelton and was now killing his uncle or how it had spread between them. They also had no idea how many other people might already have been exposed, including the medical team that had treated them. As the hospital moved to contain the situation, another

patient was brought in. It was Dwayne and Sandra's two-year-old daughter, Sherry Johnson. While Sherry had seemed relatively okay, small spots of blood had suddenly started appearing all over her body. Staff rushed to help the toddler. but tests showed she was already headed towards liver failure and had a minimal chance of surviving. Meanwhile, Dwayne Johnson's organs began shutting down. At 10.25am on Friday, September 15, one day after the death of his nephew, Dwayne also passed away. Within minutes, it was decided that all remaining family members should be brought to the hospital and quarantined.

Sally and Bruce Shelton, who were still recovering from their illness and grieving the loss of their child, were admitted, along with Sandra Johnson and her three-month-old son, Michael, who were the only ones seemingly unaffected. Along with Sherry, they were all placed in strict isolation. Anyone entering their rooms had to wear protective gowns and masks. Nurse Linda Rummel urged her staff to be careful, warning, We don't know what we're dealing with here. With the death count at two, the city's health department was called in and the Centers for Disease Control or CDC was notified.

On the morning of Saturday, September 16, the day after Dwayne's death, more than 30 doctors and public health officials gathered in the hospital's conference room for an emergency meeting. There were two questions on the agenda. What was killing these families? and was it contagious? They went through every detail of the two cases. Autopsy results showed that Chad Shelton and Dwayne Johnson had died from catastrophic liver

damage and brain bleeding. Dwayne's brain in particular was so ravaged that whole sections had been eaten away, leaving behind empty holes. The patient's bodies showed no sign of bacteria, infection or virus, which meant that what ever killed them was likely not contagious. The pathologist believed they'd most likely been exposed to a toxic substance such as contaminated food or some sort of chemical. The problem was, toxicology tests had found nothing. Desperate to find the source and prevent any more deaths, a team of public health officials descended on the Johnson's home. The small house was half yellow

and half blue, as Dwayne Johnson had been in the middle of painting it when he'd fallen sick. Inside, the team went room to room looking for anything that could be contaminated. In the kitchen, they seized a half-eaten sandwich along with samples of tea, sugar, lemonade powder and a plastic jug. In the yard, they took samples from the soil, pipes, air conditioner and various plants. An officer canvassed the neighbours to see if anyone else was. was sick or had noticed any strange chemicals or odors. When they'd finished, they drove to the Shelton's home and started the process all over again. By the end of the day, they had dozens of samples, but nothing that seemed a likely source of the toxin. Meanwhile, an epidemiologist from the

CDC was working a different angle. J.P. Lofgren was convinced there must be a common link between the family members who'd gotten sick that excluded those who hadn't. Given that vomiting had been the first symptom and all five patients had fallen sick on Sunday September 10, Lofgren thought the likely culprit was something they'd had to eat or drink that day. He interviewed Sandra Johnson, who recalled that on Sunday morning she'd made Sherry a bowl of cereal with milk and herself a cup of tea. When Dwayne got up, he had a glass of milk. but stopped drinking it because he said it tasted strange. Thinking it must have expired, Sandra tipped the rest of the milk down the sink.

Mid-morning, she took the children shopping while Dwayne stayed home to paint the house. It was a hot day and he kept cool by drinking a cold beer and some lemonade, which Sandra had made a few days earlier using a packet of lemonade powder. Meanwhile, at the shops, Sherry began vomiting. By the time they arrived home, Dwayne was vomiting too. He and Sherry had both laid down to rest and hadn't been the same since. Sandra's younger sister, Susan, also lived at the house. She told Lofgren that she had poured herself some of the lemonade that morning,

but it had tasted strange, so she'd spat it out. Sally and Bruce Shelton told Lofgren they assumed their vomiting had been caused by the tacos they'd purchased from the Mexican restaurant on Sunday night. But given that Sally had first vomited before eating any, Lofgren wasn't so sure. He discovered that between going shopping and to a birthday party, the Sheltons had dropped in to visit Sally's sister, Sandra Johnson. When they arrived, Sandra Wurton. warned them that Duane and Sherry were sick in bed, but had invited them in for a quick drink

of lemonade. Bruce had shared his with Chad, while Sally finished her whole glass. It was a short visit, and they left soon after. It was the only time that weekend that they were all in one place. In the days that followed, the two families had barely spoken, each preoccupied with the sickness in their own households, the Shelton's with what they thought was food poisoning, and the Johnsons with what they thought was the flu. But piecing the stories together, Lofgren quickly spotted a pattern. The five people who'd consumed lemonade or milk had gotten sick, while those who hadn't, three-month-old Michael, who only drank formula, Susan, who'd spat out the lemonade, and Sandra, were fine.

When Lofgren shared his belief that there had been something toxic in the drinks, health officials were relieved. Though they still had no idea what the toxin was or how it got into the drinks, they no longer had to worry about a communicable disease, or as the newspapers were calling it, a mystery illness. A press conference was called and a health official told reporters that residents of Omaha could now breathe easy, as there was no ongoing threat to the public or the family.

But not everyone was so sure. Case file will be back shortly. Thank you for supporting us by listening to this episode's sponsors. Thank you for listening to this episode's ads. By supporting our sponsors, you support CaseFile to continue to deliver quality content. Lieutenant Foster Burchard was head of the homicide unit at the Amahar Police Department. Over the previous week, he'd come across two stories in the Omaha World Herald about an uncle and young nephew who'd died, possibly from drinking a toxin. To Bertad,

the whole situation sounded strange, and he wondered whether it was something the police should be involved in. On Tuesday, September 26, he rang the County Health Department and was put through to an epidemiologist named John Wiley. Wiley's first words were, Am I glad you called? He explained that although they still weren't 100% sure, the health department was confident the deaths of both Chad Shelton and Dwayne Johnson

were caused by a toxin. But they had no idea what kind and whether the patients had ingested it by accident or because of deliberate poisoning. Lieutenant Burchard understood that the department had been focused on the health of the patients and the public, but, given the circumstances, he was incredulous that nobody had thought to contact the police. Within a matter of hours, Omaha PD formally launched an investigation. The case was assigned to Detective Kenneth Miller.

As soon as he got up to speed, Millett noted that more than two weeks had passed since the victims first fell sick. Not only that, a team of health officials had tramped through the crime scene. Key evidence had been sent off to the CDC, nothing had been checked for fingerprints, and the autopsies had been carried out by hospital pathologists looking for disease, rather than forensic pathologists searching for evidence. The investigation was already on the back foot, but Miller was determined. to make up for lost time.

He paid a visit to Sally and Bruce Shelton, who still believed that Chad and Duane had died from a mysterious illness. Told that a toxin was involved and that it might have been deliberate, the couple could hardly believe it. They told the detective they couldn't think of anyone who would want to harm their family and were stunned at the possibility that someone would want to hurt a baby. Bruce didn't even like lemonade. He'd only had a glass because Sandra had bought him one. To them, none of it made sense. Detective Miller was aware that Sandra and Sally's younger sister,

Susan, had taken a mouthful of the lemonade but spat it out straight after. He spoke to Susan, who explained that she had told Sandra immediately after that the lemonade tasted bad. She assumed Sandra would throw the rest away. but a few hours later, she had served it to the Shelton's. For the detective, a pitcher was forming. Not only had Sandra Johnson made the lemonade and not had any, Susan's account was proof that Sandra knew it was bad and didn't seem to care. He sat down with Sandra and bluntly asked her why she hadn't thrown the lemonade away

when Susan said it tasted strange. Sandra appeared to bristle at the question. She said she hadn't taken Susan seriously because she was nine months pregnant and had been complaining that things tasted funny for weeks. As for why she hadn't drunk any herself, Sandra said she didn't like lemonade and never had. Something about Sandra Johnson's reaction didn't sit right with Detective Miller. He began contacting people she'd known at high school to find out more about her background. He also staked out her house and tailed her when she went out.

He noted that Sandra was often smiling and seemed happy, even though her husband had just died. One day, Detective Miller received a phone call from the priest at the church Sandra attended, letting him know that their congregation had raised money to help Sandra during this difficult time. Before the priest handed the money over, he wanted to check whether Sandra had been faithful. to Dwayne, or if she had been engaging in any, quote, hanky-panky. Detective Miller was taken aback by the question, but he told the minister he was not aware of any infidelity. In fact, Miller had been told by those who knew her best that Sandra and Dwayne's marriage had been a happy one. When word got back to Sandra that a detective had been contacting

people from her past, she rang the police department to complain. Detective Miller took the call, during which he lost his temper. He told Sandra that he wasn't the only one suspicious of her. Her own minister doubted her intentions too. Despite all this, Detective Miller couldn't find anything that implicated Sandra in Chad and Dwayne's deaths. But he had learned about two men from her past who might have reason to resent her. Sandra Johnson had met Jim Murphy at a high school dance in 1968, and they quickly became an item. Two years later, when Sandra was still at school, they eloped.

Jim's parents were furious. They didn't think Sandra came from a good enough background for their son and tried to get the marriage annulled, but Jim wouldn't hear of it. Sandra and Jim's relationship was volatile from the start, and their arguments often turned violent. The worst one ended with the Jim punching Sandra so hard she collapsed on the floor. He then phoned Sandra's mother, telling her to remove her daughter from his house. Sandra's mum and two brothers hurried over to find Sandra unconscious on the kitchen floor. It was only when her body twitched that they realised she was. wasn't dead. The marriage ended soon after, and Sandra filed for divorce in June of 1973,

just days before their third wedding anniversary. The other ex-partner that Detective Miller heard about was Stephen Harper. Shortly after her marriage with Jim Murphy ended, Sandra asked her brother to set her up with someone else. He phoned Stephen Harper, a 20-year-old veterinary student who he knew from high school. As a child, Stephen had been in an accident which caused severe burns to more than half his body. As an adult, he was painfully shy and self-conscious of his scars. He'd never so much as held hands with a girl, let alone had a girlfriend. When he told his parents that a girl had agreed to go on a date with him, they were overjoyed. Stephen himself could hardly believe that someone as beautiful and popular as Sandra Johnson would want to be with him.

Unlike Jim Murphy, Stephen Harper was known to be kind and thoughtful. He was the kind of person who neighbours asked to look after their homes and cars while they were travelling. One time, he even cared for his neighbours' disabled daughter for days at a time while they were away. Sandra and Stephen had an on-again, off-again relationship for a year or so, before it eventually fizzled out. After that, Sandra began seeing Dwayne Johnson, whom she went on to marry and have two children with. Detective Miller asked Sandra whether either of her exes might want to hurt her or her family. While she said that Jim Murphy had been a bad apple, she hadn't seen him in years. As for Stephen Harper, she remembered him fondly, describing him as peaceful and a really nice guy.

Despite these assurances, Detective Miller ran both names through the police database. They both came back clean. At a loss, he decided to pay a visit to Sandra's mother, Jean. Miller had already spoken to Jean earlier, but hadn't learned anything new. Since then, Jean had had time to think. She told Detective Miller that while Sandra loved her children way too much to have done poisoning herself, she couldn't shake the feeling that she had somehow contributed to the deaths. Jean had straight up asked Sandra if she'd been involved, and Sandra had simply said no,

without any emotion, which Jean found odd. She also told the detective that Sandra had always been the type to bring trouble on the family and on herself. When Detective Miller asked what she meant, Jean pointed to a scar on her cheekbone. She told him that a few years back, one of Sandra's old boyfriends had opened fire on the family and Jean had been shot in the face. Miller was dumbfounded. He'd never heard about a shooting

and asked Jean why she hadn't mentioned this before. She explained there'd been no reason to. The man who'd shot at them, Stephen Harper, couldn't be involved. He was still in prison. When Detective Miller got back to the station, he went straight to his computer. Shooting was a felony, which meant something should have come up when he'd run Harper's name through the database. But the department's IT system was old and glitchy, especially when several people were using it at once.

This time, when he typed in the name, there was a hit. Three years earlier, on June 20, 1975, Stephen Harper had got into an argument with his father and threatened to shoot him. Eventually, he drove off in a rage. He contemplated killing himself, but then decided to kill his ex-girlfriend instead. Harper knew where Sandra and Dwayne Johnson lived, so he drove to their street and found a vantage point where he could spy on the newlyweds house, which happened to be across the street from Sandra's parents. At 1am, a car pulled up and six people got out, Sandra and Dwayne Johnson, Sally and Bruce Shelton, along with Sandra and Sally's brother, Dan, and his date. The group had been out for pizza and a movie and were planning on having

some more drinks inside. Before they made it to the door, Stephen Harper's car screeched to a stop, in front of the house. Dan was the first to recognize the driver, and he yelled at Harper to leave his sister alone. Sandra went over to ask Harper to leave, and saw that he was holding a 4-10-gauge shotgun. Harper began firing shots at random, and the group scattered, taking shelter wherever they could. Harper got out of the car and advanced on Sandra, who had crouched down by the back wheels. He pointed the gun at her and demanded to know where Dwayne was. Harper then turned and fired at Dan multiple times, hitting him in the head and face.

Hearing the commotion outside, Sandra's mother, Jean, cried out. Harper fired at her too, before jumping in his car and driving off. Police were called to the scene and the injured parties were rushed to hospital. Dan was lucky to survive and only narrowly escaped brain damage. Jean was left with facial wounds and had been half an inch away from losing an eye. The police couldn't find Stephen Harper anywhere. Scared that he might come after them again, Sandra and Dwayne moved out of their home and went into hiding.

A few weeks later, Jean found an envelope in her letterbox addressed to Sandra. Though she had no proof, she was convinced that was from Harper. More letters arrived over the coming weeks, including one that wasn't postmarked and therefore must have been hand-delivered. They all said the same thing. Dwayne will never have Sandy. Police were notified, but the letters continued. The next one contained cut-out pictures depicting Sandra as various satanic figures, always. with bare breasts.

On July 10, 1976, more than a year after the shootings, a traffic cop stopped a man on his motorcycle and ran his name through the system, only to discover there was an outstanding warrant for his arrest. Stephen Harper was officially arrested and charged with shooting with intent to kill. He pleaded no contest. Harper's defense lawyer said the incident was nothing more than an attempt to resolve a problem, with the girlfriend and assured the court that his client had already learned his lesson the hard way. In a letter to the judge, Harper spoke of his deep remorse and his desire to help alleviate the grief

he'd caused his victims. The judge sentenced him to a maximum of five years in prison with hard labour, declaring, this young man must learn that using a weapon is not the way of solving his problems. After reading through Stephen Harper's file, Detective Miller was left with more questions than answers. He still couldn't believe the shooting hadn't been mentioned earlier, although with Harper behind bars, he could understand why the family might have thought it wasn't important. What he couldn't understand was why Sandra Johnson had called the man who'd shot at her family nice and peaceful. Miller rang the Nebraska State Parole Office to confirm the dates in the file, and discovered that Stephen Harper had actually walked out of prison almost a year earlier

in November 1977, and no one had thought to notify Sandra or her family. His parole had lasted for three months, and he'd been a free man ever since, having been deemed to present no risk to the community. The parole board had no idea about his current whereabouts. The last they'd heard, he was planning to go to university in the neighbouring state of Iowa. If Harper was living in Iowa, Detective Miller thought he might not have been involved in the poisoning after all. He began making inquiries and within a few hours he confirmed that while Harper had applied to go to Iowa State University, he'd never actually enrolled. The Iowa address he'd listed on his application was also fake. On its own, this story.

didn't prove anything. Miller still needed to find out if Harper had been in Omaha around the time the families fell ill. On a hunch, he ran a search for any paperwork from the past month that mentioned the surname Harper regardless of the first name. One case popped up. A 16-year-old boy named Michael Harper had crashed his motorcycle on September 6, four days before the suspected poisoning. The next day, Michael had been unable to collect the paperwork from the police station himself and had sent his older brother to get it for him. Detective Miller stared at the signature on the bottom of the form. Stephen Harper hadn't just been in Omaha around the time of the poisonings. He'd walked into the police station and signed his name. Later that week on September 28, Detective Miller received

another call from the state parole office. After their last conversation, the parole officer had gone back through Stephen Harper's file and found a list of places where he'd worked after his release. Given what Miller had told him about the case, there was one entry which he thought would be of interest, the Epley Cancer Research Institute. As soon as Miller heard the name, he placed a call to the health department to tell epidemiologist John Wiley. For a moment, there was no response.

When Wiley finally spoke, he told Miller it wasn't the first time the Institute had come up in the case. Someone from the CDC had mentioned it to him that morning. Dr. Renata Kimbrough, a pathologist and toxicologist at the CDC, had spent weeks trying to identify the toxin that had killed Chad Shelton and Dwayne Johnson. She began by testing the samples taken from the Johnson's kitchen, including the tap water, lemonade mix, sugar and plastic jug, but they all came back clean. She moved on to the tissue samples.

At a microscopic level, most of the samples from Chad and Dwayne's organs looked relatively normal, but the liver tissue showed catastrophic damage. This in itself was an unusual signature for a toxin, Dr Kimbrough began testing for poisons known to single out the liver, including arsenic, selenium, bromide, weed killer and various fungi, but they were all negative. She expanded her search parameters, testing for more obscure toxins. The problem wasn't that she couldn't find any matches, it was that she couldn't find anything.

By Monday, September 25, she was out of ideas. She rang John Wiley at the health department to tell him she could not identify the toxin. Officially, Dr. Kimbrough was reassigned to other cases, but in her spare time, she kept coming back to the tissue samples. Then, on the morning of September 28, she finally spotted something. Dr. Kimbrough was examining a slide of Dwayne's hepatic lobules, the microreyses, the microreau. aeroscopic units that make up the liver, when she realized that the damage was only in the centre of the lobules while the outer parts were unharmed. It was a highly unusual pattern, but she'd seen it before. Although further testing would be required, she was confident

the toxin was from an exotic class of chemicals known as alkaliating agents. These chemicals were not typically found in a domestic setting or even a standard pharmacy. In fact, Dr. Kimbrough had only ever seen it used in research projects, and she could only think of one place in the whole of Omaha that might have it. She picked up the phone and called John Wiley. Wiley listened to her findings, but the science meant nothing to him. Then Dr. Kimbrough asked her big question, Did any of the victims have a connection to the Epley Cancer Research Institute?

At the time, Wiley thought the idea seemed far-fetched and had brushed off the suggestion. But with the same name being brought up by Detective Miller, he realised Dr. Kimbrough had been on to something. It was a turning point for Detective Miller too. Dr Kimbrough had just confirmed what he'd suspected all along but been unable to prove. Chad and Dwayne had not ingested the poison by accident. Someone had murdered them. Within days, police secured a search warrant for Stephen Harper's home. Inside, they found an open chemistry textbook, surgical gloves and an empty glass file.

There were also handwritten notes about an experiment he'd been conducting, tracking how long different animals had taken to die. The garage, which was covered in animal droppings, contained five empty rat cages. Outside, officers searched the yard for dead or buried animals. Near the garage, they found a mound of dirt marked with a wooden cross. Digging revealed a plastic bag containing the remains of a dog. Stephen Harper's father, who lived a few doors down, was watching the search. He told officers it was their family pet who died of heartworm.

While numerous items were seized, nothing in the house directly linked Harper to the Johnson or Shelton families. And although police thought Harper's experiment seemed suspicious, he had a known interest in veterinary science. It was possible there was an innocent explanation. To rule it out, Detective Miller visited the Epley Institute. He learned that Stephen Harper had been a low-level employee whose work mainly involved caring for lab rats. He hadn't been involved in running experiments and none of the chemicals he'd had access to were particularly toxic. Frustrated, Detective Miller even followed up with the vet, who confirmed that the family's

family's dog had in fact died of heartworm. It seemed like every lead was turning into a dead end. Then, on Sunday, October 8, on what was supposed to be his day off, Miller's phone rang. It was Ron Betton, another of Sandra's brothers. He'd just been at church where he'd heard an interesting story about the Harper family. Apparently, a month or so before Chad and Dwayne died, two of the Harper family's pets, a cat and a dog, had been rushed to the vet and died. Detective Miller tried to let Ron down gently, telling him they already knew about the dog who had died of heartworm. But Ron insisted that this was a different dog at a different vet, and he had it on good authority that the animals hadn't died of natural causes.

They'd been poisoned. Case File will be back shortly. Thank you for supporting us by listening to this episode's sponsors. Thank you for listening to this episode's ads. By supporting our sponsors, you support CaseFile to continue to deliver quality content. The next morning, Detective Miller was waiting outside the Northwest Animal Clinic before it opened. He introduced himself to the vet and asked whether he remembered an incident about a month or two ago, involving a dog and a cat being poisoned.

Dr Ernest Summers remembered it well. On August 7, a woman named Eva Lou Harper, Stephen Harper's mother, brought an eight-week-old Doberman to the clinic. The puppy was suffering from seizures and an extremely high temperature, with symptoms that included vomiting and uncontrollable bleeding. The vet tried everything, even organising a blood transfusion, but after two days, at the clinic, the puppy died. While this was going on, another member of the Harper family walked into the clinic

holding the family's cat. The animal was clearly in pain and couldn't stand up or walk. He commenced treatment, but the cat soon died too. Dr. Summers suspected that both animals had been killed by the same poison. To Detective Miller, the animal's symptoms sound. sounded eerily familiar. If he could prove that they died from the same poison that killed Chad Shelton and Dwayne Johnson, it would be the first concrete link tying Stephen Harper to the murders. But there was a problem. The animal's bodies had been collected by the Humane Society weeks ago.

Detective Miller headed straight there, only to be redirected to a landfill site. When he explained that he needed to find the bodies of two animals, a bemused employee told him that 2,000 animals came through their facility every month and they were buried under thousands of tons of garbage. It was another dead end, but even without physical evidence, the statement from the vet tipped the case over a critical threshold. Although the evidence was all circumstantial, there was now enough for an arrest warrant, Detective Miller was still convinced that Sandra Johnson was somehow involved and had either conspired with Stephen Harper or somehow tricked him into murdering her husband. He tried to convince

the prosecutor that Sandra should be arrested too. The prosecutor declined, pointing out that there was no evidence whatsoever implicating Sandra and that not liking someone didn't mean they were guilty. The police investigation had managed to stay under the race. with the public still under the belief that Chad Shelton and Dwayne Johnson had died from a medical mystery that was still being managed by the Health Department. When a press conference was held on October 12 to announce that the case was being treated as a homicide and an arrest warrant had been issued, the news therefore came as a shock. Stephen Harper was charged with two counts of first-degree homicide for the murders of Chad and Dwayne, as well as three counts of poisoning

relating to Sally and Bruce Shelton and two-year-old Sherry Johnson. The police revealed that they didn't know Harper's current location but believed he had left Nebraska, and they announced that the FBI had been brought on board to assist with the arrest. The media frenzy that followed ensured that Stephen Harper's name and image were broadcast into thousands of homes. Within a matter of hours, two separate tips had come in, revealing that Harper was living and working 800 miles away in Beaumont, Texas.

By the next morning, the FBI tracked him to an airport where he was attempting to flee. On October 13, four weeks after the deaths of Chad and Dwayne, Stephen Harper was placed under arrest. Later that day, a team from Omaha traveled to Texas to interview their suspect. When a prison guard went to get Harper from his cell, they found him sitting sitting. in a pool of his own blood holding a shard of broken glass. He had scrawled the name Sandy on the wall in blood. Harper was bandaged up and taken to the interview room, where he informed the team that while he would like to answer their questions,

he'd been advised not to talk without his attorney present. The officers huddled outside in the hallway. They knew that anything Harper said from this point on would likely be inadmissible in court and that continuing to question him could jeopardise the whole case. But two-year-old Sherry Johnson was still sick and her doctors had no idea what poison they were trying to treat. They all agreed what they had to do. Detective Greg Thompson entered the interview room alone. Thompson was known for his ability to play the good cop and build rapport with suspects.

He apologized to Stephen Harper for the way Sandra Johnson had treated him, saying she never should have left him. Detective Thompson told Harper that he knew what he did was an accident and that he never meant for a child to die. He said that if Harper came clean, he'd avoid the death penalty. In fact, he wouldn't even go to jail, but would be put in a mental health facility where he could get help. Harper questioned these statements,

but the detective assured him he'd been given. given authority to make such promises. If Harper preferred, they could even speak off the record, then nothing he said could be used against him. With that, Harper started talking. I did it, he said. He told the detectives he'd had to do it because he was still in love with Sandra Johnson. While he was working at the Epley Institute, he often saw lab rats get injected with a chemical that gave them cancer. It had given Harper an idea and he'd stolen a bottle of the poison. For most of August, 1978, he stalked Sandra and her new husband, Dwayne, to learn their routines. Then on the night of September 9, he broke into their house and searched their kitchen

for something suitable to poison. In the fridge, he found a jug of lemonade. He pulled out the vial of poison, tipped most of it into the lemonade and the rest into a bottle of milk, then fled the scene. Harper said it never occurred to him that anyone other than Sandra and Dwayne might consume the drinks. He also hadn't meant for the poison to kill them straight away. He thought the chemical would take years to work, so that when Sandra and Dwayne eventually got cancer and died, no one would ever realize it had been murder. As for the fact that Sandra didn't like lemonade, it was unclear whether Harper hadn't known this about his former girlfriend or if he'd simply forgotten.

Asked what the name of the chemical was, Harper said it was called DMBA. With that, he was taken back to his cell while detectives raced to find a phone. Back at the CDC, toxicologist Dr. Renata Kimbrough began conducting. experiments. DMBA, short for dimethyl benzodiazephrasein, is a carcinogen, a chemical that causes cancer, used to induce tumours in lab animals. But when Dr. Kimbrough fed it to rats, the dose required to make them sick was extremely large, far greater than what could be added to someone's drink without them noticing. Whatever poison had been in the lemonade, it wasn't DMBA. While Stephen Harper may have lied about which chemical he'd used, investigators wondered if other details he'd given were correct.

They visited the Epley Institute for a second time and spoke to the director, Dr Philippe Shubik. On hearing the victim's symptoms, Dr. Shubik agreed that DMBA could not be responsible. But he knew of another chemical they kept at the Institute that was a far better fit. It was called dimethyl nitrosamine, or DMN for short. It too was used to induce cancer in lab animals, but unlike DMBA, it only affected the liver. It was also tasteless, odourless, and dissolved easily, making it easy to hide in food or beverages, and only a small amount was needed to cause catastrophic damage. Just 2.8 grams could kill a fully-gorithms.

grown adult. However, Dr. Shubik warned that proving it was DMN would not be easy. The chemical metabolizes in the body very quickly, with most of it breaking down within 24 hours of consumption. Another 24 hours after that, and it was as if it had never been there. He explained, that's why none of the tests done on Chad Shelton and Dwayne Johnson would have found anything, because there was nothing left to find. In the weeks after Stephen Harper's arrest, an anonymous call came into the prosecutor's office. The caller suggested they speak to a man named Bill Trout,

who had information about the poisonings. Bill Trout had been in prison at the same time as Harper, Harper for the shooting incident and Trout for embezzlement. Trout's name had come up in the investigation before, once when police found a postcard he'd sent to Harper, then again when his number was found in Harper's phone records. Both instances had been deemed unimportant, but with this tip coming in, investigators set out to find him.

Detective Miller discovered that Bill Trout had moved to California on September 13, 1978, three days after the murders. With their interest peaked, Detective Miller and the police, prosecutor flew to the West Coast. It took a lot of persuading, but eventually, Bill Trout agreed to answer their questions. According to Trout, Stephen Harper had been obsessed with his former girlfriend Sandra Johnson for years. During their time in prison, he talked openly about killing Sandra, and had said multiple times that if he couldn't have her, nobody could. When Harper and Trout were out on role, the two men often chatted on the phone or met up for lunch. During one conversation, Harper

told Trout about his new job, where he had access to a toxic chemical that caused cancer. Harper called the toxin fantastic because you only needed a tiny amount to kill someone, and it was virtually impossible to detect in the body. It was such an ideal murder weapon he even talked about selling it to other people who wanted to kill someone. Harper told Trout he intended to use the toxin on Sandra Johnson and her new husband. He'd even conducted an experiment on his parents' pets to make sure it would work. Harper had put some of the poison into a bowl of milk in his garage where he knew the family cat would drink it. He hadn't anticipated that their puppy would also like milk and it ended up drinking some too.

Harper was surprised by the speed and intensity with which the animals died. Realising he'd used too much poison, he resolved to be more conservative when poisoning Sandra and Dwayne so that they wouldn't die too quickly. Investigators already knew that the Harper family's cat and puppy had died from an apparent poisoning before the murders. Bill Trout's account was confirmation it had been a deliberate test run. Bill Trout said that Harper had discussed various ideas for carrying out his plan. At first, he wanted to send Sandra and Dwayne a box of candy as a belated wedding gift. He later changed his mind, telling Trout he planned to break into their house and hide the

toxin in some food or drink. That way, his name would never come up, and they'd never even know they'd been poisoned. Down the track, they'd develop cancer. cancer and die. Asked why he didn't warn anyone or call the police, Trout said he never thought Harper would go through with the plan, calling it hot air. The fact that Trout had left Omaha so soon after the murders was pure coincidence. His parole conditions had changed on September 13, allowing him to travel interstate, so Trout left for California that same day. A friend occasionally mailed copies of the Omaha World Herald newspaper to his new home so that he could keep up with local news. It was only when reading one of them that Trout saw a story about the deaths and figured that

Stephen Harper must have followed through on his plans. Then, on October 13, Trout said he received a call from Harper, looking for any tips on how to leave the country. When Trout asked why. Harper said he'd carried out his plan to poison his ex-girlfriend and two people had died, so he was about to be arrested. The prosecutor could hardly believe his luck. He still had no idea who'd tipped them off about Bill Trout, but whoever it was had handed them the one witness who could testify that Harper had planned the murders in advance. There was just one more person he needed to prepare before the trial. As the intended to be the intended to be the trial, as the intended target of the crime, Sandra Johnson was set to be a key witness. But when the prosecutor

tried to arrange a meeting to go over her testimony, he couldn't find her. Her family didn't know her whereabouts either. In the month since her husband Edwain had been murdered, Sandra's life had unraveled. Not only had she suddenly become a single mother of two with no reliable source of income, she'd also had to watch helplessly as her eldest child. continued to suffer. Two-year-old Sherry was still experiencing strange symptoms and had endured numerous trips to the hospital. At some point, Sandra had withdrawn from the people around her and moved with her children to a small town north of Omaha. When the prosecutor finally tracked her down, he discovered that in February 1979, five months after Dwayne's death, Sandra had remarried.

For some, the timing of this new relationship seemed suspicious, but the prosecutor was unwavering in his position that there was no evidence to suggest that Sandra was anything other than a victim. Even Stephen Harper himself, who openly blamed Sandra for leaving him, had never blamed her for the crime. From his first police interview in Texas to his years of conversations with Bill Trout, he'd only ever described acting alone. Still, the prosecutor later admitted to a reporter that he was caught off guard by the news that

Sandra had remarried so quickly. He'd been expecting to put a grieving widow on the stand, but instead would be questioning a newlywed. Although he wasn't sure how it would sit with a jury, at the end of the day, it wasn't a crime for a widow to remarry. The trial against Stephen Harper began in September 1979. As predicted, his confession to the police was ruled inadmissible, which meant the state's case was largely circumstantial. Bill Trout and Sandra Johnson testified, but the prosecution's biggest hurdle was proving the identity of the poison itself.

For this, they relied on toxicologist Dr. Renata Kimbrough. In the lead-up to the trial, she'd exhaustively studied the pattern of damage in the victim's tissue and confirmed that it was. was consistent with damage caused by DMN. Dr Kimbrough had also devised a blind test for another leading toxicologist who'd reached the same conclusion. It still wasn't 100% definitive, but it was as close as the science of the day allowed. The defence initially wanted to argue that Harper could not be held responsible for the murders due to insanity, but this idea fell through when their own psychiatrist determined that Harper

was sane. Instead, they tried to cast doubt on DMN as the murder weapon, pointing out that it appears naturally in trace amounts in foods such as peanut oil and bacon, and therefore could have come from anywhere. In total, the defence case lasted for only 37 minutes. After one day of deliberation, the jury returned their verdict. Stephen Harper was found to guilty on all five charges. In delivering his sentence, the judge pointed out the slow and agonising nature of the victim's deaths. He wrote, By any standard, the murders of Dwayne Johnson and Chad Shelton were conscientious, pitiless, and unnecessarily torturous. A more horrible death than that endured by the victims can hardly be imagined.

He sentenced Stephen Harper to death. With the trial over, the Johnson and Shelton families filed a civil suit against the Epley Institute, arguing that it had been negligent. Not only had they hired a convicted felon to work alongside deadly chemicals, the chemicals weren't even secured properly. Due to its extreme toxicity, the DMN was kept in a locked refrigerator, but the key was kept in an open container right beside it. There was no monitoring system to keep track of the chemicals. allowing Stephen Harper to steal a vial of Daemon without anyone ever realizing it was gone. The lawsuit also alleged that while Harper was working at the Epley Institute,

an employee had pinned an article to a notice board about a crime that took place in Germany. In 1975, a woman in the town of Ulm began experiencing strange symptoms. For two years, doctors tried to determine the cause of her illness but were unsuccessful. Eventually, the woman started bleeding from her nose and mouth and was admitted to hospital. She became suspicious when her husband, a chemistry teacher, kept bringing her jars of marmalade. The marmalade was tested and found to contain DMN. The woman's husband had been secretly feeding it to her for two years. She died of liver failure shortly after being admitted to hospital and her husband was found guilty of murder.

In their lawsuit, the Johnson and Shelton families argued that by displaying this article, the Epley Institute had inspired Harper's crimes, while simultaneously giving him access to the rare poison he needed to execute his plan. The court disagreed, and the case was dismissed, with the Institute avoiding any liability. Stephen Harper avoided his full sentence, too. The state of Nebraska had an execution. anyone in 20 years, so there had been doubts from the start whether the state would ever enact his death penalty. In the end, the question was irrelevant. In 1990, Harper took his own life in his prison soul after hoarding his own medication and swallowing a toxic dose. The impact of

Harper's crimes did not end with his imprisonment or even his death. Sandra Johnson's subsequent When marriage ended, when her new husband got upset after an argument and tried to set their mobile home on fire with Sandra and the children inside it. Sherry Johnson was two years old when she drank the poisoned lemonade. She survived thanks to blood plasma treatment, but continued to experience strange symptoms and required outpatient care. The DMN caused permanent damage to her liver, which doctors warned could one day turn cancerous. Sally and Bruce Shelton survived the poison that killed their 11-month-old son, but their life was never the same.

On top of the grief of losing their only child, they were told it was highly likely that they'd develop cancer in the future. This caused immense stress, not least because they both longed for another baby. Sally was convinced she wouldn't live long enough to raise a child, and couldn't bear the thought of leaving an orphaned baby behind. To her, it felt like Stephen Harper had robbed her of motherhood all over again. Sally and Bruce eventually divorced. Bruce spent years battling ongoing health issues, depression and housing insecurity,

before succumbing to liver damage and alcoholism at the age of 37. Sally remarried in 1990 and rebuilt her life as best she could. She became a local icon in her new neighbourhood, starting a community garden with her new husband, Chris, and ensuring local children had a safe place to play. Chris told the Omaha World Herald that Sally had a natural bond with kids and that her passion for protecting them grew out of great loss. Though Sally worked hard to live a joyful and active life, she couldn't escape the damage done to her body. Over the years, her constant symptoms took an even greater toll. In September 2014, 36 years after drinking the lemonade poisoned by Stephen Harper,

Sally's liver finally failed. She died on her and Chris's wedding anniversary at the age of 57. Of his wife, Chris said simply, She was sweet and beautiful.