I saw this in Summer 2001 in the UK and it left a huge impression on me. It was a mystery thriller and the main character was a married woman living in a big city (NYC, maybe). She kept receiving death threats from her husband’s ex-lover who was sending her letters and phone-calls using a very distinctive voice. On one occasion, the ex-lover even hit her on the head in a cemetery with a shovel which hospitalised her. The woman was then escorted by police who began to investigate this ex-lover using her name. An old detective working on this case found some trace on this woman’s name in a mental institution and was totally shell-shocked by what he discovered. He drove back to his office, not knowing that he was followed by this very same person. The next scene we saw this detective stabbed with the shaft of a vintage disc player. The story built towards a climax, namely the very date that the ex-lover swore that she would get to the woman and when the bell rang midnight, the woman, lying in bed with her husband, grew anxious. She heard noises from outside the bedroom and her husband went out to check. She then heard ruckus and went out to see. She found her husband wounded and bleeding. She then hugged him but then her husband whispered in her ear in that very distinctive voice, revealing that it was he all along pretending to be this ex-lover and it was his plot to murder her and claim the insurance money. Things were moving according to his plan until some physical fight ensued and the husband died. The woman survived and in the end all was revealed to her: while in mental institution, her husband adopted the name of that ex-lover whose details the old detective discovered which led to his death. The woman was safe after all and the film ended on a very sinister and ambiguous note.
This was one hell of a scary film but I really would like to find out what it was. It was in English- probably American given its style, tone and colour, though not certain. Any help would be most appreciated. Thanks in advance!