Continuity mistake: When Norman arrives home, he is startled by a note that is found beside the phone and he accidentally knocks his suitcase down the stairs and most of his clothes land on the top of the stairs. But as the camera angle switches to the bottom of the stairs, the clothes are further down the staircase. They couldn't have moved as they were stationary at the end of the other shot. (00:10:15)
Continuity mistake: When Norman is painting the motel, he is distracted by someone looking out the curtains of his house and he drops the paintbrush straight. But in the next shot the paint brush has moved at a forty-five degree angle to how it landed. (00:43:55)
Continuity mistake: When the two teenagers are down in Norman's fruit cellar, and a "lady" with a knife is chasing the boy, he leaves finger markings on the fogged up window. But by the next shot they have changed. You can tell because when the boy made the markings, his thumb and his index finger markings intersected, but when the camera angle changes the finger prints don't intersect and they are noticeably straightened also. (00:49:45)
Continuity mistake: Near the end where a lady is coming up the stairs to the Bates house, her hair is tied up much like the "Mother" wig, but when the lady arrives, who turns out to be Mrs. Spool, her hair is parted very differently. (01:40:40 - 01:41:10)
Continuity mistake: After Norman argues with Mr Toomey, before he goes up to the house, you can plainly see the light on in the living room where Mary is sitting. When Norman goes in the house, Mary is sitting in the dark and Norman then turns on the light.
Continuity mistake: Norman picks up the note from his "mother" on the order wheel at the diner. He reads it then drops it on the floor. You can see it on the floor yet it's gone when everyone goes back in the kitchen. So where did it go? All the employees were out of the kitchen.
Continuity mistake: After Mary takes a shower, she steps out and of course she is completely wet. 3 seconds later her body is completely dry.
Continuity mistake: Norman hits Mrs Spool over the head with a shovel. Immediately after the blow, the camera cuts to an overhead view, and the saucer on the table is suddenly shattered, as is the kitchen chair in which she is sitting, even though they received no direct impact.
Answer: Norman was found "not guilty" by reason of insanity. Therefore, once he is deemed to be no longer a danger to himself, or to others, and is released from the mental institution, there is no crime he can be sent to jail for (i.e. he has no criminal record for the murders). I haven't done enough research to tell you if a serial killer in recent times has ever been found not guilty by reason of insanity and subsequently been released, but there are numerous accounts of people being released from mental institutions after committing murder that are then considered free.
Bishop73