Call Me Avenged. Sondra Dillinger Chronicles, #3

When people start going missing in a small Northeast Texas town, Sondra Dillinger steps in to solve the case of a missing pair of twelve-year-old twin boys. She soon learns that two common denominators exist between the people who have gone missing: abused animals, and a local animal rescue owner, Loretta Bentley. Unbeknownst to Sondra, Loretta's deep devotion to animals is overshadowed by mental illness and her belief she is getting messages from God to deliver an-eye-for-an-eye justice to anyone who neglects or abuses animals.
Many have thought this penalty deserved, but Loretta is insane enough to carry it out on her isolated, large ranch where no one can hear her victims' screams.