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

More on John and Lauren's Hidden True Crime podcast | Dateline NBC

Today on a new Dateline: True Crime Weekly, Andrea Canning has the story of a former Olympian accused of being a drug kingpin responsible for several murders, a big ruling in the Mangione case, and a verdict in the trial of a Virginia man accused of masterminding a double murder. Listen now: https://podcasts.apple.com/us/podcast/verdict-in-double-murder-trial-olympian-accused-of/id1745566056?i=1000748321316 | Dateline NBC

None of it made sense… What happened on that cold, brutal morning? Find out tonight at 9/8c on a classic Dateline on NBC. | Dateline NBC