Sita is the main villainess from "Bollywood Homicide," a fourth season episode of Psych.
She was played by Lisa Ray.
Sita was engaged to be married to Jay, but after meeting Jay's brother, Raj, she developed feelings for him. Unfortunately for Sita, Raj was taken, and since he would never betray Jay in any form (including dating his future wife), Sita took matters into her own hands and sabotaged Raj's relationships, including his current one with his fiancee, Mina; doing so by nearly killing Mina. Sita's actions caused Raj to believe that he is cursed and he is the reason that something bad always happens to his girlfriends. To find the attacker, Juliet poses as Raj's latest girlfriend, and at episode's end, Shawn and Gus find Sita holding Juliet at knifepoint. Juliet fights Sita off and she is arrested.
In a deleted scene on the Psych Season Four DVD, the evil Sita revealed that she planned to kill Jay, hoping that her grief and Raj's would bring them together.