Help with a scene please...possible Bava movie?

Hi, I know this film starts with a murder aboard a train, but I am looking for a different movie. The scene also takes place on a train, and it's daylight. The train employees are looking for a woman passenger, who they know is missing. After a while of searching for her aboard the train, they find her dead in the train bathroom.
I think her father or stepfather was involved...like he told the police that she would be aboard the train so they knew to look for her there.
Does this sound familiar to anyone? I think it's an Italian horror film, possibly Bava, but I'm not sure.