There is a guy, who wants to have a best selling book. One day, a new neighbor arrives, this new guy happens to be also a writer, so the first guy goes and shows him a manuscript of his book. The new guy reads it, and he realizes that it's going to be a best seller so he goes to his neighbor's house to talk to him. But when he goes there are police cars surrounding the house, and they tell him that his neighbor is dead. He decides to publish the book as if he was the author, and this brings him fame and fortune until one day some people (I don't know if they are police officers) arrive to his house to ask him about the book since it contains information and precise details about many murders that only the killers would know. That's all the information I got, please help me find it.

Certainly sounds familiar! But can't remember the name... however Im pretty sure the once I am thinking of was a Stephen King adaptation or maybe a Koonitz... sorry not to be able to help further... do you know who acted in it?

No, I'm sorry, I can't remember the actors or the year of the movie, only the plot.

Try this:
A Murder of Crows Reviews & Ratings - IMDb
There's also this: ( a bollywood remake of A Murder of Crows... )
http://en.wikipedia.org/wiki/Fox_(film)

(Moogue, I think you're thinking about either Secret Window, or The Dark Half... )

Thank you, this is the movie :)

:)