Most nights during the early summer of 2011, Chukwuemeka Ene would slip out the back door of a bungalow in Jackson, Mississippi, and make his way to a nearby convenience store. He didn’t mind the Deep South’s steamy heat; it reminded him of the climate in his hometown of Enugu, Nigeria. Ene was seventeen years old, but at six feet three inches tall, he might easily have been mistaken for a man in his twenties. This was particularly true when his broad features took on a brooding expression — and in Jackson, he wasn’t smiling much. Back at the house,…