Internal Affairs is the twelfth episode of Season 5 of CSI: Miami.
Nick is murdered in his condo and Natalia is arrested for the crime when evidence at the scene suggests she killed him, but Horatio tries to clear her name. The evidence also reveals that Delko and Nick fought earlier in the day. In another case, a wealthy single man is found dead in his mansion with a granite-topped bookshelf on top of him. The investigation reveals the victim was seeing a therapist who suddenly dropped him as a patient. It is suddenly discovered, that the two cases are related.