The last woman in the forest / Diane Les Becquets.

Enhanced descriptions from Syndetics:

From the national bestselling author of Breaking Wild , a riveting and powerful thriller about a woman whose greatest threat could be the man she loves....

Marian Engstr m has found her true calling- working with rescue dogs to help protect endangered wildlife. Her first assignment takes her to northern Alberta, where she falls in love with her mentor, the daring and brilliant Tate. After they're separated from each other on another assignment, Marian is shattered to learn of Tate's tragic death. Worse still is the aftermath in which Marian discovers disturbing inconsistencies about Tate's life, and begins to wonder if the man she loved could have been responsible for the unsolved murders of at least four women.

Hoping to clear Tate's name, Marian reaches out to a retired forensic profiler who's haunted by the open cases. But as Marian relives her relationship with Tate and circles ever closer to the truth, evil stalks her every move....