An easy way to get the Unsolved Acheivement

[some1stoleit]

Getting this achievement is much easier than it seems, here's what you have to do:

1. Introduce yourself with your real name in the Introduction.
2. Go to the bathroom and grab the wrench, don't talk to anyone.
3. Use Atma and/or Mistress Chevalier's services, when talking to them choose the submissive dialogue options and don't talk to them about themselves or others.
4. Wait in Chevalier's room until 9:50.
5. Kill Frank and then escape to the middle floor landing.

The detective won't have a lot to say to you during the interrogation, and it should be obvious what to say to avoid suspicion.

It's a logical way to make the case unsolved, given how none of the characters have a real motive to kill Frank and you've only been in the brothel as a patron rather than asking questions about Frank.