>> reporter: brittany stork had done the unexpected, persuaded law enforcement to dust off a thirty year old case file -- her mom's. >> she's a force of nature, i think. >> it's -- it's -- she is. >> reporter: doug kinder is an investigator in the prosecutor's office. he inherited the case when the first investigator retired. he also inherited those weekly phone calls from brittany checking up on him. >> give me some adjectives to describe brittany. >> determined. unrelenting. tough. >> was she tough to deal with? >> no, not at all. >> was she a squeaky wheel you wish would go away? >> no. she just wanted answers. >> did you wish she weren't doin' it, toby? >> no. when i found out what she was doin', i just didn't want her to be pushed to the side like it never mattered.