Case Sensitive (2011)

The tragic deaths of Geraldine Bretherick and her young daughter Lucy in their upscale home leave investigators grappling with a perplexing case. Newly appointed DS Charlie Zailer and her partner DC Simon Waterhouse find themselves at odds over whether it was a murder-suicide or a more nefarious act, particularly as they scrutinize the alibi of the grieving husband, Mark. Meanwhile, Sally Thorne, a mother of two, is unsettled by the news, recalling her brief affair with Mark months earlier. Ignoring her friend Esther's warnings, Sally feels compelled to reach out to him in his time of grief.