Episode air date: May 8, 1991
In 1989, Patricia Stallings was wrongfully accused of murdering her infant son Ryan with antifreeze when lab results showed that he had a high level of ethylene glycol in his blood. While in prison, Stallings gave birth to her son David, who was put in foster care while she awaited trial. David was diagnosed with methylmalonic acidemia (MMA), a rare genetic disorder that can mimic antifreeze poisoning. Stallings's lawyer believed Ryan may have had the same condition, but didn't have any evidence. Thus, the judge forbade him from presenting this theory to the jury. In 1991, Stallings was convicted of first-degree murder and assault.
After watching the Unsolved Mysteries episode on Stallings, biochemistry professor William S. Sly decided to do additional tests on Ryan's blood and confirmed that Ryan had died from MMA, not poisoning. In the summer of 1991, Stallings was released, her charges dismissed, and her son David returned to her.