Two elderly, wealthy spinster sisters in Llano, Texas, die within a day of each other, and it is chalked up to an unfortunate coincidence and old age. After all, they were seventy-five and eighty-three years old, respectively. One month later, an elderly man in San Angelo, Texas, 130 miles from Llano passes away, and it is attributed to old age and poor health. But there would prove to be a couple of common denominators, Tim Scoggin and poison.

This case proved to be ground-breaking in legal annals in the use of atomic testing of cremated ashes along with testing of hair for poison, setting a precedent for evidence in court.

Since that time, there have been several cases where this type of evidence has been used. It was featured on Forensic Files on Court TV, with McKinnon being interviewed along with several other individuals involved in the case.

Tim Scoggin remains in Texas prison. Prison officials say it is unlikely that he will ever be released. This is the story of how and why.