In Psycho who seems to killed Marion Crane in the shower?

Answer 1

NOT Norman Bates brother.

It "seems" to be Norman's Mom who killed Marion.
But After Norman's arrest, a forensic psychiatrist tells Sam and Lila that Norman's dead mother is living in Norman's psyche as an alternate personality.

Answer 2

Either 7 or 8 times. I think it's 8 times, but it's hard to tell if the knife actually penetrated flesh on the first blow. Norman might've just stabbed the air the first time.

I played it back so many times -- actually, I rented the movie JUST to answer this question -- but I just can't tell. You can sort of hear the sound of the knife stabbing flesh on the first blow, but the sound isn't nearly as pronounced as it is with the 2nd, 3rd, 4th, 5th, 6th, 7th, and 8th stabs, which you can hear very clearly.

By the way, the sound effect they used for the sound of the knife penetrating flesh is actually the sound of someone stabbing a casaba melon.

Answer 3

Norman Bates's Mother. But.....
After Norman's arrest, a forensic psychiatrist tells Sam and Lila that Norman's dead mother is living in Norman's psyche as an alternate personality.

Answer 4

Norman Bates' Mother