Norman's father *spoiler*

*SPOILERS*

Ms Spool did kill Mr. Bates, but she could have set a bunch of bees on him. Here's everything I think for all four movies.

Ms Spool was in love with Mr Bates, but he didn't return those feelings, so in a jealous rage kidnapped baby Norman, but he was saved, and then she set a bunch of bees on his father, killing him. They say at the end of Psycho 1 that Norman was disturbed after his father died, and then his mother's abuse made it worse, but he still loved her and tried everything in his power to make her happy. Then she brings home Chet Rudolph, and he is rude to Norman, punches him, giving him a bloody nose, and his mother doesn't defend him, just laughs at him. Her attention is now on Chet, and none of it is on Norman. All the years of abuse and neglect have finally sent him over the edge, and so he poisons his mother and her lover.

After that, he's put into an asylum, not because they think he murdered them, but because he found their bodies, and so that's why they put him away. Then he's let out, and he gets back his mother's body, and turns himself into her, to try and rid himself of the guilt, and he goes crazier and crazier. His mother would never let him do anything, and she was crazy, so he probably figured if he became attracted to any woman, then mother would kill them. Norman is found out, locked back up for 22 years, declared sane, gets out, goes crazy again, and is locked back up. He meets his future wife, Connie, who helps him, and this time he gets better. He's not cured, but he's better. The residents probably wouldn't welcome him back again, so he moved in with Connie in another part of California.

Joseph Stefano wanted to ignore parts 2 & 3, but he didn't do a very good job. No offense to him or anything. But the murders from part 2 and 3 are implied in the story. And it shouldn't be called part 4 if he wanted to ignore 2 and 3. He should have called it Psycho: The Beginning if he wanted to ignore the other sequels, but called it Psycho IV: The Beginning. But yes, Ms Spool set bees on his father. Maybe he was allergic, and Ms Spool used that to her advantage.