. >> stay out of the bagwell case or you and your family will face the wrath of god. >> it's, i guess kind of a veiled threat. no one ever knew where it came from. >> at nancy's autopsy the pathologist found no signs of disease in her internal organs. but toxicology tests revealed some surprising results. nancy lyon had been poisoned with arsenic. >> all the specimens showed significant amounts and levels of arsenic. and what that shows is that the poison was absorbed through the gi tract, that it was distributed through the blood. >> patients often don't know they're poisoned since the symptoms are so common. >> people don't think about a poisoning immediately. they think it's just a natural thing. and when you have nausea and vomiting, that certainly is a common symptom. >> most of the poisonings that you see nowadays are of a much more sophisticated variety that are harder to detect initially or even after doing tests. so, arsenic was a surprise. >> the manner of death was ruled a homicide, but questions remained. investigators discovered a receipt among nancy's papers, a receipt f