Violet Summers (Abigail Spencer) is the alias used by the main villainess in the Killer Instinct episode Love Hurts.
She and her husband are serial killers, they take it in turns to flirt with a target, luring them to a location (like a hotel room) where the other partner kills the victim, they then behead them.
Violet is the first to lure a target, she meets a businessman in a club and gets him to drive to her friend's place, but on the way Violet's husband shoots the man with a crossbow through the car windshield which causes him to crash, he is then beheaded.
Violet and her husband meet in a car park, he shows her the victim's head in a box and she seems thrilled and says she loves him, they then kiss passionately.
Next is Violet's turn to do the killing, her husband lures a girl in a bar to a hotel swimming pool after hours where Violet has set a trap in the water. The girl goes into the pool and steps on the trap, which grabs her leg and pulls her underwater, she is unable to surface for air and drowns. She too is then beheaded.
The police are on the couple's trail though, and discover that they use aliases and have killed in 5 different states already. Detective Jack Hale is sent in to a club undercover to be Violet's next victim. She leaves the club with him and they go back to her house, not the hotel room she originally suggested, which is where the police listening in on Jack's wire are heading. This leaves Jack alone with Violet and her husband in the house without police assistance.
In the house, Violet discovers Jack's wire, her husband shows up and tells Violet to grab Jack's gun. Jack manages to grab it back off her though and shoots at the husband before running away upstairs to escape. Violet then grabs a gun from a metal case and she and her husband hunt Jack upstairs. Jack bursts out of a wardrobe and knocks the husband down. The police then show up, having worked out the house's location, their arrival startles Violet who turns and shoots in their direction, however her husband was in the way and she accidentally kills him. Violet screams in anguish and is devastated, she is restrained by Jack and is arrested.