Tom Rob Smith seems like a nice enough guy, but many of his works are about grisly murders. His newest project is ‘The Assassination of Gianni Versace,’ FX’s second entry in its American Crime Story anthology. The series examines the murder of the fashion icon, and looks at the lives of the other men who died at the hand of killer Andrew Cunanan. Smith tells us why writing about murder is a useful way of exploring a society.