What's with all the wild theories? SPOILERS
I don't think this film was great, but I liked it.
I'm just surprised how totally lost most viewers are... Its almost as if they've gotten so used to having all the motives thrown straight at them, that they expect everything to be written in silver lining...
FEW THINGS:
1. The real murderer is of no consequence to this movie. He is irrelevant. His murders are relevant to the plot, but whodunnit does not matter.
2. Any loose threads or semiloose threads are also irrelevant. The also reason they are relevant is because of how they put the main character in deep trouble.
3. We are shown at several times several versions of the same truth, seen through the eyes of various people. The main situation is the Carmine scene. The Belucci character remembers it erotically. The Hackman character remembers it innocently. This leads to misconceptions and misunderstanding which ruin the marriage.
4. The film is a psychological drama of a man broken, who essentially after believing that his wife has no faith in him, has essentially betrayed him and sees him as a rapist and murderer, decides to admit, even though he is innocent.
5. In the end scene the Belucci character sees that she was wrong to doubt and is full of guilt. She alsohas possible refound the love and trust she once lost. The Hackman character is broken, distrustful and essentially possible rid of his love to his wife. Hence Monica tries to approach him, whilst Gene avoids contact.
I guess part of this is owned to inept direction, but still...