The sole survivor of an attack in which four people were murdered identified the perpetrators as three white men. The police ignored suspects who fit the description and arrested a young black man instead. He is now awaiting execution. Guests: Kevin Cooper, who has been on death row at San Quentin State Prison in California for three decades; Nicholas Kristof, a New York Times columnist who has written about Mr. Cooper’s case. For more information on today’s episode, visit nytimes.com/thedaily.