I read this thriller manga many years ago and the only things I remember are that the mc was a boy (maybe a detective, but I'm not sure), there was a park that was very important for the plot, there was a stalker (I'm not really sure about it, but probably) and I remember that the killer used to keep the body parts of their victims inside the fridge (like a common fridge, not a very big one). That's all I can remember, someone knows its name?