In Longmont, CO, Tammy Tatum is brutally murdered right near her one-year-old daughter, Sadie. Now 24, Sadie reveals to Chris Hansen the shocking truth... that the killer was someone she knew her entire life.

The brutal shooting of Stephen Perret looks like a mob hit. Police have little evidence, but soon discover Stephen made a call just before he was murdered. Chris tracks down the person Stephen called... who reveals the identity of his killer.

Detectives searching for wealthy scientist Walter Sartory believe he's been kidnapped and is being held hostage for his fortunes. Chris Hansen discovers that investigators were in a race against time to find Walter before it was too late.

College senior Susannah Chase had everything to live for, but just a few days before Christmas she was brutally attacked only yards from her home. Chris Hansen travels to Boulder, Colo., to discover the shocking truth behind her murder.