 Stella Nickell ( born August 7 , 1943 ) is an American woman who was sentenced to 90 years in prison for product tampering after she poisoned Excedrin capsules with lethal cyanide , resulting in the deaths of her husband , Bruce , and Susan Snow . Her May 1988 conviction and prison sentence were the first under federal product tampering laws instituted after the Chicago Tylenol murders . 
