Investigators have used polygraph — lie detector — tests to effectively rule out potential suspects in the Nancy Guthrie disappearance, NewsNation national senior correspondent Brian Entin reports. #Crime #NancyGuthrie #LieDetector Get a fast-paced look at the latest from the border to Main Street to the White House on "NewsNation Live" with Connell McShane. Weekdays starting at 3p/2C. NewsNation is your source for fact-based, unbiased news for all Americans. More from NewsNation: newsnationnow.com Get our app: trib.al/TBXgYpp Find us on cable: trib.al/YDOpGyG How to watch on TV or streaming: trib.al/Vu0Ikij