>> -- this is a long time ago? >> reporter: but brittany didn't stop there. she says she marched into the police department that had first handled her mom's case and demanded to see the police chief. >> you're just cold walking in on these people? >> uh-uh. and i basically said, "i either want someone to investigate what happened to her, or i want her file and i'm gonna take it somewhere else." >> reporter: a detective promised to see what he could find out but apart from the odd phone call, brittany says it felt like her mom's case went nowhere. and before she knew it months turned into years. brittany's life moved on. married now, she had another baby. she was a dance teacher. then one day she ran into the original detective who'd worked her mom's case . >> i'm at a restaurant with my wife eating, and this lady comes up to me. and i -- i didn't know her, didn't recognize her. and she says, "mr. bratton, i'd like to talk to you." "well, sure, sit down." >> and i said, "i'm dana rosendale's daughter" and all three of their mouths about dropped to the table and i said "i wanna know what happened to my mom." and he just said -- "you know, you need to keep pushing" and that's all he'd say. >> reporter: so she did.