The release date of the movie seems to be July 2012.
Residents of a small apartment building learn that a serial killer lives within their building.
A stepmother (Kim Yunjin) feels heavy guilt for not being able to prevent her stepdaughter's murder. The stepmother takes it upon herself to find the killer. Meanwhile, a young girl (Kim Sae-Ron) that resembles the murdered girl becomes the next target of the serial killer.
Here is a photo of Yunjin Kim and Kim Sae-Ron on set on the last day of filming:
sources: 1; 2; 3