A murder mystery in Kentucky. A prosecutor on a mission. And a murder weapon on the rise.

In a town of 4,000 people, a Facebook group of 10,000 asking what happened to a woman stabbed to death. 15 years after thousands of untested rape kits were found, Kym Worthy tells us how she's making sure a backlog like that never happens again. And why are there so many poisonings lately?

If you or someone you know has experienced sexual assault, call the National Sexual Assault Hotline at 800-656-4673 or visit online.rainn.org for more resources.