Murder of the Sheriff

When the Sheriff of West Feliciana Parish is found murdered in his own jail, Niki Dupre is called in to investigate.
Soon, Niki learns that a local chapter of the infamous MS-13 gang is responsible. But they are hired thugs; gangs do not kill sheriffs without getting paid.
The more Niki delves into the murder, the more entangled she gets with the local gang and their leader, Juan Valdez. And he doesn't play by the rules.