Jen (Charlotte Arnold) is the main villainess from Private Eyes' second season opener, "The Extra Mile" (airdate May 25, 2017).
Jen is an EMT, but her backstory reveals that she was the girlfriend of Danny Gibson, who was involved in a drag racing related accident that included famous racer Eric Mantella. Eric's car clipped Danny's, sending Danny crashing into a lamppost and losing his leg, while Eric fled the scene. Jen was distraught over what happened to Danny and wanted revenge on Eric, especially after learning about his involvement in the accident.
However, Danny (who never knew who it was in the other car--a classic black Mustang) felt the opposite, and their relationship ended due to Jen's obsession. The break-up would fuel Jen's rage, as she stalked Eric and sent threatening letters to him in the three months leading to the episode's events. The letters were delivered before Eric's races in Daytona, Winnipeg, Knoxville, and Corpus Christi--races that Eric ended up losing. In the beginning of the episode, Jen wrote a personal message in blood, stating that he'll die if he races, and she later set fire to the Mantella garage.
Jen's role was revealed after Matt Shade and Angie Everett visited Danny, who mentioned Jen and her profession. The episode's climax saw Jen spotted and pursued by Angie, while Matt was attempting to talk Eric's mother, Emila, into stopping the race. After Angie catches Jen, she asked what she did with Eric, only for Jen to state that it was too late. The villainess later defended her attempt to kill Eric (later revealing that she laced his water bottle with a sedative) and ranted about how Eric ruined her life, only for Angie to respond that Danny didn't believe his life is ruined and later asking Jen to tell her what she had done. After Matt saved Eric by driving the emergency truck and causing a red flag to stop the race temporarily, Jen was later arrested for the threats and the attempt to kill Eric.