Former national security adviser Michael Flynn leaves the U.S. District Court in Washington, D.C., in late 2018. Saul Loeb/AFP via Getty Images hide caption

Construction at the COVID-19 field hospital at McCormick Place in Chicago on April 10. The city pared back plans for a 3,000-bed temporary hospital at the nation's largest convention center as infection numbers decreased. Nam Y. Huh/AP hide caption

The East Bay Municipal Utility District wastewater treatment plant in Oakland, Calif. Stanford University researchers are testing sewage in hopes of tracking the emergence and spread of COVID-19 outbreaks. Justin Sullivan/Getty Images hide caption

Georgia Anne Muldrow was Robin Dann's choice on the last episode of Play It Forward. Muldrow moves the chain of gratitude along to saxophonist Lakecia Benjamin. Priscilla Jimenez/Courtesy of the artist hide caption

The U.S. Supreme Court overturned the conviction of key aides to New Jersey Gov. Chris Christie in connection with the "Bridgegate" scandal. Richard Drew/AP hide caption

PwC is testing its new contact tracing app in Shanghai, to keep track of how close employees get to each other in the office. PwC hide caption

A public health nurse and National Guard medic interview a patient before taking a swab for COVID-19 testing at Gallatin High School on April 19. This was one of dozens of Tennessee sites where even patients without symptoms were welcomed to get a free test, paid for by the state and processed by private lab companies. Blake Farmer/ WPLN hide caption