CSI: NY (2004)

S01E20 Supply and Demand

After a college student is brutally beaten, shot, and his apartment looted in what looks like a drug-related execution, the team springs into action to identify his murderers. Investigating the crime scene reveals traces of raw, unrefined heroin and leads them to discover that the victim had a female roommate who has since vanished. At the same time, Stella's intense questioning approach with a witness puts her badge in jeopardy, raising concerns about her methods.