Here's a review of VIPER from Carl Brookins, writing for the blog "Criminal Minds at Work":
Set in rural Illinois, the novel follows disgraced DEA agent Selena De La Cruz as she tries to re-order her life into some semblance of normality after a drug raid gone bad results in a tragic aftermath. Leaving that life turns out to be more than just difficult. It is impossible. And so Selena leaves her insurance company and re-enters the dangerous world of undercover drug enforcement among a Latino population that is turbulent, ever-changing and marked with friends who become enemies and family members short on understanding.
The author cleverly establishes Selena as an independent capable woman beset on all sides by the chauvinism of her bosses and the cultural disapproval of her family. Good Latinas do not carry guns and arrest drug dealers. There is an invasive Latin Catholic presence throughout the book. The basic theme of the story is a list of names entered into a church’s Book of the Dead, requesting prayers for their souls. The problem is that the people represented are still alive as the book opens. But one by one they are murdered. Since Selena’s name is last on the list, she has more than usual reason to be concerned. Her interaction with law enforcement and Church officials becomes more and more intense as the list is shortened, one by one.
The novel is smoothly written, logical and mostly gripping. There are several sections of Aztec and other religious history and legends used by the author to explain some of the ritual Selena encounters which, while interesting in themselves, have a tendency to slow the narrative. Nevertheless, Viper is a worthwhile read, blending religious mystery with brutal modern crime.