In 1989, a toddler died of a rare condition. As a result, his mother would be convicted of his murder, and only released after an episode of Unsolved Mysteries brought the case to the attention of a biochemist at Saint Louis University.
On July 7, 1989, in Jefferson County, Missouri, a three-month-old Ryan Stallings was rushed to a St. Louis hospital by his parents, Patricia and David Stallings. He had been refusing to feed over the last day, as well as breathing too fast and appearing increasingly lethargic.
Tests conducted on the boy found that he had unusually high levels of ethylene glycol in his blood, leading his team to believe that he had been poisoned with anti-freeze.
"Because the parents could not account for the child's apparent exposure to ethylene glycol and because of other factors in the social history," a team that would eventually exonerate Patricia Stallings wrote in a case report, "the [infant] was placed in protective custody."
About eight weeks later, in unfortunate timing for Stallings, she visited her son, who was under the care of foster parents. The next day, the boy began vomiting, had muscle spasms, and started to hyperventilate. Again, high levels of ethylene glycol were found in the patient's blood. On September 4, he died. Antifreeze was found by authorities at the home of Patricia and David Stallings, and the day after that she was charged with the murder of her son.
Adding to the tragedy of the situation, Patricia Stallings was pregnant. She gave birth to her second son while still awaiting trial, and the second boy – David Jr – was placed into foster care. A month after his birth, you guessed it, he began to experience symptoms similar to his deceased brother, despite having zero contact with his mother. He was quickly diagnosed with a rare genetic disorder – methylmalonic acidemia (MMA) – which would explain not only his symptoms, but his brother's death as well.
MMA is a group of genetic conditions which prevent the body from breaking down certain parts of proteins and fats. As a result, toxic substances build up in the body, often resulting in serious illness, as well as symptoms such as lethargy and trouble breathing. One of the substances that can build up in the body is propionic acid, which, as a team would later explain, can easily be mistaken for ethylene glycol.
It all sounds quite open and shut at this point. A boy died of apparent poisoning by anti-freeze, before his brother was diagnosed with a genetic condition that can mimic the effects of antifreeze poisoning. However, it wasn't over yet. Stallings' lawyer was aware of the genetic condition but failed to bring sufficient evidence to the trial in order to get Patricia exonerated.
When the lawyer suggested that natural causes could have been at play, the prosecution responded that "you might as well speculate that some little man from mars came down and shot him full of some mysterious bacteria.”
She was convicted of first degree murder, and assault, and sentenced to life in prison. The following year, an episode on the case appeared on Unsolved Mysteries.
Biochemist William Sly of Saint Louis University was watching the episode, and he and the Director of the Metabolic Screening Lab at St Louis University, Dr James Shoemaker, were able to test Ryan's blood, which confirmed that he had had the disease.
However, since ethylene glycol is not produced in humans – even in those who have MMA – and the prosecution believed that this substance had been found in Ryan's blood, this still wasn't enough to convince the prosecution that he died of natural causes.
Still not done, Sly asked to know the methods used to determine that ethylene glycol had been found in Ryan's blood. He then sent samples of blood containing propionic acid to commercial labs, who analyzed the samples using the same methodology used in the initial investigation. Sure enough, about half of the labs came back with incorrect results, confirming the team's suspicions.
"The gas chromatographic peak identified as ethylene glycol by a clinical laboratory was actually due to propionic acid," the team wrote in a 1992 paper. Sly went on to show that other indications of antifreeze poisoning could actually have been because of interventions that were given to the patient, on the assumption that he had been poisoned.
Shortly after this evidence was presented to the prosecutor, in July 1991, Stallings was released and reunited with her second son, while awaiting a new trial on the grounds of inadequate legal defense. Soon after that, the charges against her were dismissed.