The Secret Service is being criticized for closing its investigation into a bag of cocaine found at the White House without a culprit. Former agent Evy Poumpouras joined "Elizabeth Vargas Reports" to explain how an investigation like this is conducted and what challenges the agency might have faced as they looked into the matter. #WhiteHouse #WestWing #Cocaine #DNA #Fingerprints #SecretService More #VargasReports: newsnationnow.com/joinus Anchor Elizabeth Vargas delivers the biggest stories, without bias or opinion. Watch "Elizabeth Vargas Reports" every weeknight at 6p/5C on NewsNation. #VargasReports NewsNation is your source for fact-based, unbiased news for all America. 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