Kayna Whitworth reports on the Colorado dentist guilty of murder in the first degree after authorities say he was secretly and systematically poisoning his wife by lacing her protein shakes; Trevor Ault has details on one of the largest recorded earthquakes that struck off Russia's Pacific coast, prompting tsunami waves and panic from Russia to Japan to the U.S., the 8.8 magnitude quake triggered Russia's largest volcano to erupt; Pierre Thomas has the latest on Virginia councilman Lee Vogler attacked and doused with gasoline then set on fire; and more on tonight's broadcast of World News Tonight with David Muir.

Trump envoy visits Gaza as humanitarian crisis worsens; Manhunts underway in Tennessee, Montana for suspected killers in separate shootings; Trump moves US nuclear submarines in rare warning to Russia.