Twisted (2004)

Recently elevated to the homicide division, Inspector Jessica Shepard faces the daunting task of proving her worth. Her opportunity arises with a high-profile murder case in San Francisco. As Jessica and her partner, Mike Delmarco, delve deeper, they uncover a shocking link: the victim had been romantically involved with her. As the bodies of her former lovers continue to surface, Jessica finds herself spiraling into uncertainty. Her grip on reality weakens, leaving her tormented by the chilling suspicion that she might be the killer she is desperately seeking.