Grissom's Divine Comedy - S8-E12
Continuity mistake: When Warrick demands to see the hands of a suspect, the suspect refuses and Warrick pushes him up against a wall. During which time, there are multiple angles which show Warrick wearing sunglasses, then suddenly not wearing them anymore. (00:23:30)
Answer: The episode on CSI:NY was called "Love Runs Cold" and first aired on October 4, 2006 (Season 3, Episode 3) and involves the investigation of a model found stabbed to death by an ice dagger.
OneHappyHusky