A woman's death from a unknown illness only became more mysterious when she was found to have died with extremely high levels of arsenic in her system.
Investigators keyed in to a suspicious bottle of wine that had been left at her door shortly before she became ill. But then they learned her husband had been working on developing a new kind of pesticide -- one which contained arsenic...
An HLN Mysteries special, "Beloved and Betrayed" takes a closer look the case Saturday and Sunday night at 7 p.m. ET.