NBC Nightly News Full Episode - Feb. 17

Tonight, a major setback in the search for Nancy Guthrie. The glove found near her home not matching in the DNA database as the sheriff reveals to us the fresh leads they're now pursuing. Possible new clues in the videos. Was the suspect wearing a ring under that glove? Plus, the hope that DNA found inside the house could lead to a suspect. And the sheriff tells us that major tech companies, even Mark Zuckerberg, have reached out to help. Also breaking tonight, a man with a loaded shotgun in tactical gear r ...