>> at that point, i was banging my head against the wall. >> reporter: linda was also growing frustrated. she was now a widow, a single mom, shunned by her husband's family and eagerly waiting for a break in the case. >> reporter: a lot of time passed without an arrest. >> torturous. >> reporter: every day are you wondering, "is today the day or is it never going to happen"? >> you would kind of get through a point where you'd say, "okay, we're going to live our lives and when it happens, it happens," you know? and then they'd need something from me. and i'd get pulled back in again. >> reporter: one of those times police met with linda to explain there was a problem with the original autopsy. turns out it was incomplete because back then, no one suspected poisoning. many samples like the contents of tom's stomach that might have proved midazolam as the actual cause of death weren't saved for testing. so the d-a's office decided to do something radical.