New York Mayor: No indication chopper crash is act of terrorism, New York Mayor on crash: "There's something mysterious here", Ex-Nixon aide John Dean testifies on parallels between Watergate and Mueller investigation, Trump: "You can't impeach somebody when there's never been anything done wrong", Department of Justice: Barr's review of the beginnings of the Russia probe will be "Broad in scope and multifaceted", Watergate witness John Dean testifies on Capitol Hill as Democrats begin series of hearings on Mueller report, Ex-White House Counsel John Dean tells Congress he sees similarities between Nixon and Trump, South Korean President: Dialogue with North could resume soon; Speculation grows about third Trump summit with Kim Jong Un via Knit