What does Maddux say he knows about Harpo Scruggs?

Maddux tells Robicheaux that a man by the name of Harpo Scruggs worked as a guard at Angola Prison forty years ago. Around that time, Scruggs was responsible for the murder of a young black man. Maddux also informs Robicheaux that fifteen years ago Harpo Scruggs died in a fire in Juarez, Mexico, while in the company of a prostitute.