The Dark Mirror (1946)
A woman suspected of murdering her doctor boyfriend has an identical twin sister. When both twins have an alibi for the night of the murder, a psychiatrist is called in to assist a detective in solving the case. Through a series of tests, he discovers which twin actually committed the crime and in the course of his investigation he falls in love with the normal twin.
When Dr. Frank Peralta is found stabbed to death straight to the heart in his apartment, two neighbors swear to the veteran Lt. Stevenson, who is charge of the investigation, that they saw Ruth Collins leaving his apartment late night. The detective interrogates Ruth and she has the alibi of three witnesses that she was walking around in the Jefferson Park during the night. Then he visits Ruth in her apartment and discovers that she has an identical twin sister called Terry. Lt. Stevenson does not know who the killer is and the prosecutor does not accept to open the case. The sisters can not find a job and Dr. Scott Elliott, who is a specialist in twins that had been contacted by Lt. Steenson and has a crush on Ruth, offers a reasonable allowance to the sisters to be submitted to a series of tests for his research of personalities of twins. Scott finds through the results that Terry is a psychotic woman and Ruth might be in danger.
When Det. Lt. Stephenson investigates the murder of a doctor, who was found stabbed in his apartment, he learns that he had dinner with a woman named Teresa Collins the evening of his death. It looks like an open and shut case when several residents of the apartment building identify the woman. It turns out not to be so easy when he learns she has a twin sister, Ruth and neither will implicate the other as being the woman who was there. A psychologist who has made a study of identical twins, Dr. Scott Elliott, agrees to look into the case and concludes that one of them is insane. Complicating matters is the fact that he is falling in love with one of them.
A man is murdered, and several witnesses can place Ruth Collins at the scene of the crime. But Ruth has a twin sister, Terry, who has been diagnosed as a psychotic. When Ruth falls for the psychiatrist who evaluates the two sisters, will Terry strike again?
A man is found murdered, with witnesses convinced about the woman they saw leaving his apartment. However, it becomes apparent that the woman has a twin, and finding out which one is the killer seems impossible.
- When a man is discover stabbed in the back witnesses point out the woman they saw at the scene of the crime, the demur Ruth Collins (Olivia de Havilland) but their eye-witness account goes bad when they see Terry Collins (Olivia de Havilland) the twin sister. During their psychically and physically connected lives the two have actually pretended to be each other for many reasons like subbing for one another at work and other activities. In this case it seems that one cant believe that the other could do anything so horrible. On the case is Lieutenant Stevenson (Thomas Mitchell) but when he realizes that he cant bring in the killer without the aid of the twin, he turns to Dr. Scott Elliott (Lew Ayres) to do a psychological profile of the women to see if the real murderess can be spotted. When Dr. Elliott realizes that one twin is an insane killer the situation turns deadly.