Plot hole: The police let Norman back to his house on the same night multiple murders happened. He is even allowed into the fruit cellar, where most of them happened. (01:38:25)
Plot hole: When Norman's doctor follows Lila to Norman's house, by the time he goes into the cellar, the killer has killed Lila, hid the body in the pile of coal, and cleaned up. Highly unlikely in a 4 minute time frame.
Chosen answer: The murderer is Emma Spool, Norman's biological mother. She was killing people because she didn't want anybody harming Norman.
Emma was not Norman's biological mother. She was the sister of Norma (and Norman's aunt) and jealous that Mr. Bates chose Norma over her and thought Norman should have been the son she and Mr. Bates were suppose to have. Later, while still mentally ill, she believed Norman was her son and told Norman this.
Bishop73
Emma Spool was, in fact, Norman's biological mother. It was revealed at the end of the movie that she is his real mother and Norma Bates is her sister who adopted Norman and raised him While Emma was institutionalized.
ctown28 ★
Again, that was just Emma being delusional and/or lying. Tracy Venable tells Norman the truth in Psycho III. Emma was never his mother.
Bishop73
I never knew Emma Spool was Norman's biological mother. In fact, I never heard of Emma Spool. Thanks.