In his first interview since being fired, former FBI Deputy Director Andrew McCabe is telling "60 Minutes" why he opened up investigations involving President Trump. He was a career official at the Justice Department who oversaw the bureau's investigations into Russia's election meddling and Hillary Clinton's emails. In his new book, "The Threat: How the FBI protects America in the Age of Terror and Trump," McCabe describes extraordinary measures justice officials took in the wake of former FBI Director James Comey's firing. Scott Pelley joins "CBS This Morning" to preview his Sunday's report. Watch "CBS This Morning" HERE: http://bit.ly/1T88yAR Download the CBS News app on iOS HERE: https://apple.co/1tRNnUy Download the CBS News app on Android HERE: https://bit.ly/1IcphuX Like "CBS This Morning" on Facebook HERE: http://on.fb.me/1LhtdvI Follow "CBS This Morning" on Twitter HERE: http://bit.ly/1Xj5W3p Follow "CBS This Morning" on Instagram HERE: http://bit.ly/1Q7NGnY Get new episodes of shows you love across devices the next day, stream local news live, and watch full seasons of CBS fan favorites anytime, anywhere with CBS All Access. Try it free! http://bit.ly/1OQA29B Delivered by Norah O’Donnell, Gayle King, John Dickerson, and Bianna Golodryga, "CBS This Morning" offers a thoughtful, substantive and insightful source of news and information to a daily audience of 3 million viewers. The Emmy Award-winning broadcast presents a mix of daily news, coverage of developing stories of national and global significance, and interviews with leading figures in politics, business and entertainment. Check local listings for "CBS This Morning" broadcast times.