Dr. Kate Robbins

Dr. Kate Robbins was the main villainess from Motive 's first season finale, "The One That Got Away."

She was played by Amanda Tapping, who also played Naomi on Supernatural and Susan McQueen in Taken Back: Finding Haley.

Dr. Kate Robbins was the psychiatrist for 20-year-old Cameron Radcliffe, who was the defendant in a trial of murder he committed when he was only 10--a trial that had Angie Flynn as a juror. It was Kate's testimony that led to Angie and other juror acquitting Cameron.

Since then, the sessions continued, and in the episode's events, Kate began engaging in a sexual relationship with Cameron. She also set her villainous seductive sights on another of her patients: 17-year-old Nathan Conroy. Cameron listened in on Kate's sessions with Nathan and suspected that she was replacing him with Nathan, which promoted Cameron to kill Nathan at Kate's greenhouse. Cameron dumped the body close to Kate's office, which made her nervous, as her illicit relationship with Cameron could be exposed. To keep her secret hidden, the evil Kate manipulated Cameron into ending his life, with the "suicide" occurring in a car--with Kate placing a hose from the tailpipe inside the driver's side door.

Angie and Vega confronted Kate with the evidence at the greenhouse, and it was there that Kate claimed that Angie was using her failure to catch Cameron years ago as an excuse to pursue her. After the reveal, Angie was set to arrest Kate, only for the villainous psychiatrist to escape. She later grabbed a gun and rushed to a back barn area, with Vega pursuing her. Kate claimed that both Nathan and Cameron loved her and she fired shots at Vega in the process. Angie warned Kate to drop her gun, but when she refused, Angie shot and killed Kate.