Goodbye and Good Luck

In this episode a punk girl Kira is pushed out of her dorm room. At first glance, the CSI's think that it is a guy named Marlon who did it because he was jealous of this guy that Kira was having sex with. He was really really mad at Kira for dumping him so Sarah (who was on the case) thought it would be Marlon, he was also linked to a previous case. Then Sarah starts getting intrigued by his little evil sister Hannah who is a child prodigy and goes to the same school as Marlon. Sarah begins to think it was Hannah who did it because she was jealous of Kira and all the time she got with Marlon. Hannah didn't like Kira. Marlon and Hannah spiked the sexual lube triying to injure the couple. Sarah really believes that it was Hannah who pushed her out the window though because there is a video of her grabbing a tooth off the ground during a concert. A tooth was found imbedded in Kira's wrist. Later Marlon is put away in jail and he is then found dead, he hung himself. The part of the episode where Hannah finds the tooth isn't very plausible because if she were to plant that in Kira's wrist how exactly would that prove that Marlon did it.