She is played by Maria Russell.
Deputy Vargas first appeared in episode 6.12, "Raw Talent," as one of the deputies pointing laser beam guns at Scott McCall, who was in his werewolf form. Vargas became bewildered by Scott's red eyes, before Deputy Parrish instructed her to lower her weapon.
In the episode, "Face-to-Faceless," Vargas appeared at a scene where Quinn, a young female werewolf, was being threatened and attacked by a group of hunters. After defeating the hunters, Quinn expressed relief over seeing Vargas, but at that moment, Vargas turned heel and shot Quinn in the head. Quinn survived the shooting and revealed to Scott and his pack that Vargas is in league with the hunters and attempted to kill her.
In the following episode, "Pressure Test," the evil Vargas assisted Nolan in cutting the power in the police station, and then had Nolan locked up in a cell next to werewolves Jiang and Tierney so he could attempt to kill them with purple wolfsbane. The villainess later tossed a smoke grenade in the station; providing a distraction to allow Nolan to make his attempt, which was thwarted by Liam.