Lt. David Nelson (Greg Morris) is with the Las Vegas Metropolitan Police Department, and while he is a no-nonsense officer, he is a man who often has Tanna's back in criminal case investigations, and vice versa. While Lt. Nelson is never one to breach police protocol, he sometimes secretly assists Tanna in criminal cases his police force is prohibited from officially working on. In the first season of "Vega$", Nelson had a more adversarial relationship with Tanna, but their working friendship grows over the next two seasons.