Sandman - A Val Bosanquet Mystery. The Val Bosanquet Mysteries, #4

A former Guantanamo guard, turned al-Qaeda terrorist, is targeting Louisiana fracking gas pads using hijacked government drones. When Deputy Sheriff Val Bosanquet is seconded to the Department of Homeland Security he discovers that the usual rules do not apply. Tasked with the investigation of his friend Dave McElligott, suspected of conspiring with a domestic terrorist known as Sandman, Val follows a trail of death and destruction as he battles to prevent a bloodbath.