Movie Buffs? Question

[Spitfire]

I've been trying for a month now to figure out the title of this movie. Even my teachers can't figure it out but they know what I'm talking about. Awhile back we watched a video a teacher who left the school owned that was some TV special about movies. This guy broke down all these films and explained how the story elements worked.

In the video they showed a film that was about a detective who was convinced a murder has occurred next door to him in the hotel he was staying at. In one scene he breaks into the room next door and flushes the toilet. When he does blood appears. The character in the film looked a lot like Gordon in the new Batman films.

I can't for the life of me remember the title, the director, or anyone who was in it. I tried typing it in on search engines but with no luck. I believe the movie started with the letter "I" but I don't remember. It's been awhile so the details are quite foggy.

If any movie buffs think this sounds familiar please let me know what film you think it is. I know a lot of people now dieing to know.