This week in the magazine, Patrick Radden Keefe investigates the Amy Bishop case. In 2010 Bishop shot and killed several colleagues at the University of Alabama. In the aftermath of that crime, it was revealed that Bishop had shot and killed her brother in 1986, which Bishop and her parents have always claimed was an accident. Here Keefe and New Yorker staff writer David Grann talk with their editor Daniel Zalewski about the Amy Bishop story, non-fiction crime writing more generally, and how to approach the truth when certainty is impossible. Also, Kelefa Sanneh on drinking Scotch.