CSI: NY Episode 5.20 Prey

When the killer of a local vocal coach, Russell Baxter, sends a text message of Baxter's dead body and where to find him to police, Mac and the team find that the circumstances around Baxter's death and the evidence left behind which consists of Yak hair, volcanic ash and dry ice, sends the investigation on a wild goose chase. The victim himself surprises the team, especially when they find out he is a serial stalker whose unwavering fixation on one of the two women he preyed on relentlessly caused her to commit suicide. Mac, Stella and Det. Flack look for the second stalking victim and find that she changed her name and may be in New York City which is why Baxter came in the first place. The unusual evidence starts to come together in Stella's mind when she realizes each is similar to several separate cases she lectured students on at the local university. Stella figures out that the killer must have taken her class and quickly tries to find the student; who they also believe may be Baxter's other stalking victim. As Stella and the team close in on the killer a part of her, after seeing the harm Baxter has inflicted on his victim's lives, hopes the killer gets away but keeps true to her duty as an officer and brings Baxter's killer to justice.