The sound effect for a knife stabbing human skin as seen in the shower scene was actually a knife stabbing a sausage
Paramount originally thought the movie would never sell and therefore scrapped the project entirely.
Alfred, being rejected from Paramount funded the film by himself. He used the crew from his television series as a way to keep costs down.
The blood is indeed chocolate sauce.
The Bates motel you see in Psycho II is actually splices from the first film. After Psycho was made, the motel was torn down.
The Bates House you see in he sequel is the same house....but it was moved to a different location.
Hitchcock makes a cameo in the film. In the forth scene in Janet Leigh's office.
Both of the sequels were made after Alfred Hitchcock's death
