Killer's Identity a Surprise? *spoilers*
I've seen a review where the ultimate identity of the Killer is 'barely hidden'. However, I was caught off guard, though in retrospect, I am not sure why. Luis always was the one who had the opportunity (though the motive was not clear). It is Luis' letter that draws Isabell out at night, and Luis is the one who knows Teresa is going to leave and he is the one from the very beginning who is stalking the girls of the residence.
However, I think it was his sweet tenderness with Teresa that led me to believe it couldn't be him and that it was Mdme. Forneau, trying to kill every girls he was attracted to. That is why I was surprised at the end.
Anyone one else who was surprised?