It's a nice enough idea. 19 years ago a serial killer murdered six people over two weeks, including the mother and father of our protagonist. The murderer was never caught, and now it seems the same pattern of deaths is occurring again. It's about the past infesting the present, both literally and figuratively.
The game splits into two styles. With the DS held sideways throughout, there are information-gathering sections which see you chatting with colleagues, questioning witnesses and gathering evidence, alongside first-person portions which offer a much more hands-on experience. The latter require you to take advantage of an unusual investigating skill.