Awakening by S.J. Bolton

Clara Benning is a wild animal veterinarian in rural Dorset who avoids people because of a childhood accident that left her face scarred. She finds herself thrust into the public eye in her village when she rescues a baby from a snake that was in her crib and another neighbor dies of a snake bite. Clara wonders if the incidents were accidents or something more sinister. With the help of local policeman Matt Hoare and Sean North (a well-known herpetologist), Clara realizes that there's a killer on the loose who is using snakes as his weapon of choice. She then puts her own life on the line to try and find the murderer. Awakening is a mystery with a sense of place and loads of information about snake behavior.