Lisa Campbell was an FBI Agent who first appeared in the episode, "Demons," originally to help Ryan Hardy on his pursuit of serial killer Theo Noble. In the series finale, "The Reckoning," Lisa turned heel when she was revealed as a mole planted inside the FBI by Eliza, who was part of a sinister organization. Lisa planted a tracking device on Ryan Hardy's vehicle, which led to Eliza finding him with Theo.
After Lisa and Eliza talk on the phone, the villainous former leaves with Max Hardy to follow Theo's trail, with Max unaware of Lisa's heel persona. Max tells Lisa to call for back-up, but unbeknownst to Max, the evil Lisa took out her gun with intent on killing her. Lisa is later taken by Theo and forced to co-operate with him, and she is later found by Ryan and Max with a gunshot wound. At the end of the episode, Ryan finds Lisa hospitalized and confronts her over her actions, which led to the deaths of several agents. Lisa talks about how some serial killers are protected and have large financial means to commit their murders, but she does not give Ryan any information about Eliza or her organization. She is later (assumingly) killed by Ryan.
- Diane Neal also appeared as villainous rapist Amelia Chase in an episode of Law & Order: SVU.