Sivappu Nila (2013)

Raja is a CID inspector who is the lead investigator on the murder of the smuggler Durai. The only clue he has is that the killer rode a white horse, wore a monster mask and a black coat. In the meantime, Raja falls in love with the soft-spoken college student Raani. He then meets her look=alike, the tomboy Jhansi fighting with some goons and she lies to him that she is Raani's twin. The same killer murders another smuggler Maruthu. Raja eventually finds out that the killer is Raani (who is also Jhansi).