Victor Oquendo reports on the chaos that unfolded inside a Florida courtroom moments after Ryan Routh – the man accused of trying to assassinate Donald Trump on his West Palm Beach golf course – was found guilty on all counts, when authorities say he tried to stab himself in the neck; Rachel Scott has details on Pres. Trump's address to United Nations General Assembly for the first time since returning to office, criticizing the U.N. as a do-nothing organization that is "not even coming close" to living up to its potential; Pierre Thomas has the latest on the covert telecommunications operation in New York City that the Secret Service said it dismantled as world leaders gathered in the city for the U.N. General Assembly; and more on tonight's broadcast of World News Tonight with David Muir.