narrator: funding was also provided by, theeman foundation.oundation; pursuing solutions for america's neglected needs. and by contributions to this pbs station from viewers like you. thank you. ♪ ♪ narrator: you're watching pbs. ♪ >> good evening. i'm william brangham. >> i'm on the nevada in uvalde, texas. families mark one year since the mass shooting at robb elementary as they still unanswered questions about the police response and where their community goes from here. >> then florida governor ron desantis announces he is running for president. how his bid could shape the republican race. >> ngo's push the taliban to lift restrictions on employing women so they can deliver vital aid to afghans amid the worsening humanitarian crisis. >> it is beyond catastrophic really shared probably having the highest number of people in -- anywhere in the world.