Ariel (Dara Tomanovich) is the villainess from Diagnosis Murder episode 6.14, "Murder, My Suite" (airdate January 28, 1999).
Ariel is an evil femme fatale who was planning a heist involving millions of dollars in a safe deposit box. As part of her plan, she seduced medical student Alex Vander, and used him to acquire a vial containing Legionnaire's Disease. In the beginning of the episode, Ariel is shown injecting herself with a fake vial, only to inject the real disease into Alex. The villainess tossed the vial aside, smashing it and allowing the disease to spread.
Ariel's plan was to have the hotel she was residing in quarantined, so she could tunnel her way into the fortune. It was revealed that she had two cohorts, Herb Downey and Phil Karp, and she was using her feminine charms on both of them. In the final scenes, the evil Ariel shot and killed Karp, who was set up by Downey to be eliminated. Just as the pair were set to get away with the loot they stole, they were apprehended and arrested by Steve Sloan. During the arrest, Ariel snarls to Downey that she should have killed him when she had the chance.