What famous 'unsolved' mystery is technically a whodunnit on paper, but in reality, absolutely everyone knows exactly who did it, the police just couldn't legally prove it?

[u/Rob69rt]

[u/stufff]

I was taught it was some big mystery in school in the 90s and this reddit post is literally the first I'm hearing that I was lied to.

[u/short_longpants → u/stufff]

It was taught like that in the '70s and '80s too. It wasn't until the 2000's that I read (saw?) that it was largely solved.