For more than 25 years, Dateline has brought viewers investigations into some of biggest mysteries in America. This entry in the franchise takes a second look at some of the most mysterious cases of recent history. It explores the stories through firsthand accounts told by people who are close to the crime, including investigators who dedicated their time to the cases and family members who are still trying to confront the tragedies that befell their loved ones.

Dateline NBC, or simply Dateline, is a weekly American television newsmagazine series. It was previously the network's flagship newsmagazine, but now focuses mainly on true crime stories with only occasional editions that focus on other topics.

A series of reports chosen by "Dateline" correspondents that answers the question they most often get asked — what their most memorable story is and why.