If you are really struggling, you could look inside the scripts for the game and find it out that way. You won't get anyone directly telling you the password, those comments just get deleted.
I've never got the whole ''ooo murder mystery i wanna do that but can i have all the answers''. Its a mystery you're meant to figure out. If you want things more spoon fed, ordinary story VNs are a thing.
Why go for a mystery VN if you don't want to deal with the mystery. Though i do get it somewhat it why people read miss marple books. The mystery is engaging keeping you on the edge of your seat and you know in the end it'll all be explained. Doesn't really happen when you change the genre to one that needs your imput rather than just observing.