The Execution of Catherine Willows - S3-E6
Continuity mistake: At one point Catherine is at the coffee shop and the parents of a murdered girl come to talk to her. She is holding her coffee in the right hand and her cell phone rings and she grabs it with her left. The shot switches angles while Catherine is talking and her cell phone has magically shifted to her right hand.
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