Tia Elias (Anahi Bustillos) is the hidden secondary villainess from "Blood in the Water," episode 4.02 of CSI: Miami (airdate September 26, 2005). She is the daughter of wealthy Julio Elias, and the girlfriend of Luke Gannon (aka David Adams).
Tia began dating Luke at some point before the events of the episode, though it was never specified how long their relationship lasted. In her first encounter with Ryan Wolfe regarding the death of Luke's sister Julie (aka Molly Camden), Tia stated that the couple broke up amicably. However, it was later revealed as quite the opposite, as Tia caught Luke having sex with Julie--though she was unaware that they were con artists and not related to each other.
Angry over Luke's cheating, Tia turned heel by pouring lighter fluid in Luke's bong, knowing full well about Luke's smoking habits. When the Gannon "family" returned to their yacht, Luke lit up the bong, leading to a fire that spread all over the boat. The events of Tia's villainous revenge led to Molly/Julie escaping from the boat and jumping into the shark infested waters, where she was eaten. After Wolfe found Tia's print on the bong, he returned to the house and confronted the villainess. After denying it at first, the evil Tia confessed to tampering with Luke's bong, revealing Luke's cheating and lashing out at him for doing so with his "sister." Following her reveal, Tia was arrested for manslaughter.