in elizabeth ratliff's death, it might bolster their case. but the only way to know for sure, they concluded, was to dig up elizabeth's grave. assistant district attorney freda black. >> we decided that it probably would be worthwhile to try to exhume her body to determine whether the findings in germany were accurate or not. >> reporter: to do that, they'd have to get the okay from elizabeth's daughters, margaret and martha. the girls, who believed in their father's innocence as fiercely as they mistrusted the authorities, struggled with the decision. >> the hardest thing i've ever had to do was to write off on the exhumation of our birth mother. >> reporter: but ultimately, they agreed. >> and i signed off on it because we wanted to be, like, "there is no way this could've happened." like, please look at the evidence. i will do this to -- to free our dad of these accusations. >> reporter: on a beautiful blue