20/20 — Season 50

After a young college student is found strangled on the side of the road, the case goes cold until an eerily similar attack breathes new life into the investigation and helps enforcement catch a killer.

Allison Feldman, 31, was working in medical sales when she was found dead in her Scottsdale, Arizona, home in 2015. The crime shocked the community and left detectives with one major question: who could have committed such a violent attack without leaving an obvious connection to the victim?

Catherine "Cati" Ann Blavatsky, 22, is found dead inside a concrete box in the basement of an abandoned farmhouse. Her estranged husband goes on the run with a 17-year-old, leading authorities on a cross-country chase.

In June 2014, a highway worker cutting grass discovers two large suitcases with foul odors beside a rural road in Wisconsin. Inside, investigators find the bodies of Jenny Gamez and Laura Simonson, leaving a community shocked and searching for answers.

Dee Warner, a successful businesswoman, goes missing without a trace. A deadly mystery. Families bitterly divided. What really happened?