The big question, how often should students and teachers get tested . Top Public Health expert dr. Jha joins us live. The dramatic new experiment with lasers putting two popular face coverings to the test. Masks with valves and face shields, how ineffective are they at slowing the spread of coronavirus when used alone . What you need to see before you go out wearing one. Abc news exclusive. The Russian Election interference warning allegedly buried by the Trump Administration for two months. An alert about a russian scheme to damage joe bidens president ial campaign. Raising serious questions about who stopped it and why. Calling for justice. Breonna taylors boyfriend speaking out for the first time. I can no longer remain silent. Kenneth walker now suing the city of louisville and the police, claiming the charges brought against him were meant to silence him and cover up her murder. Bear scare caught on camera. A grizzly charging a group of hikers at Glacier National park. How they al