Investigators walked into a mystery that would turn their world upside down… Watch tonight at 9/8c on a 2-hour Dateline Weekend Mystery on NBC. | Dateline NBC

Tonight on a new Dateline, the latest chapter in this hair-raising tale, featuring new evidence, explosive testimony and the prosecution's new star witness. Watch at 9/8c on NBC. | Dateline NBC

A medical mystery was about to turn into a full-on police investigation… Tonight on an all-new Dateline at 10/9c on NBC. | Dateline NBC

Learn about a 1998 case investigators think may be connected to Scott Kimball | Dateline NBC

In an instant, a routine welfare check became a crime scene... ​Tune in tonight at 9/8c for the all-new 2-hour season premiere of Dateline. | Dateline NBC

A manhunt was underway for an apparently stone-cold killer… All-new 2-hour Dateline Friday at 9/8c with Dennis Murphy. | Dateline NBC

Thirty-two years ago this month, a series of murders began near and along Virginia’s Colonial Parkway. When it was over, four couples were dead at the hand of what authorities believe could be a serial killer. The crimes were dubbed “The Colonial Parkway Murders.” | Dateline NBC