What explains mass shootings in the US?
A movie theatre in Aurora, Colorado. Sandy Hook Elementary School in Connecticut. The Washington Navy Yard. The college town of Isla Vista, California. Most of us recognise these as US sites of recent mass murder, loosely defined as the intentional killing of more than four people in a single incident. Unlike the casualties of war or gang-related murders carried out in inner cities, these acts of domestic terrorism strike a particular brand of fear in the hearts of Americans because they seem...