A 'whodunnit' film with an obvious twist (SPOILERS)

Rating: 4/10 (15 December 2004)

I was informed by friends of mine and movie reviewers that although this movie was pretty average, the ending is impossible to guess. I can truthfully say right now that I practically saw the ending coming.
SPOILERS FROM HERE
Firstly, the thing about the 'cop' being a convict and the other con being his sidekick was extremely obvious. I first noticed how he was about to grab the key tag from the first victim without worrying about tampering with evidence. Then there was the fact that when the second convict turned up he attacked him to the point of unconsciousness so he couldn't talk. (The 'cop-being-the-killer thing may have been more obvious to me after seeing the stage production of 'The Mouse Trap').
However, the fact that the scenario was all part of a DID-sufferer's hallucination didn't spring on me until it was revealed that all of them shared the same birthday.
But finally, I found it quite obvious that the child was the murderer for a fact when he walked out the room with his mother, discovering she was dead.
I also guessed the clichéd ending how the criminal gets away with it after 'fooling' the cops/lawyers that in some way allow him to escape ('Primal Fear' and 'The Usual Suspects' to name two). I guess it wasn't an obvious fool, but I suspect the child purposely did this to reveal himself so he could escape.
So there you have it. I must say that this film doesn't deserves the score of 7.3 it currently has. A score between 6 and 7 would be more appropriate. I do believe that this was a creative twist on the 'whodunnit' where everyone's picked off one by one. However, I could've enjoyed it more had it not been so clichéd and silly at times.