Have you looked into the the drawer in Marina's Apartment (the photo)?
Viewing post in Detective Shade: The Turnabout Case jam comments
Hm... from what I know, the requirements to trigger the final scene are:
- Present all clues possible to Lucas (It's possible that certain clue presenting may be locked behind certain dialogue choices)
- Get all clues in Evelyn's Art Studio
- Get Victor to open up
- Obtain all clues in Marina's Apartment Photo
After that, you should get a popup with all requirements met and you can enter the interrogation room for the final verdict. If you're already in the interrogation room, you'll most likely need to re-enter it (Actually, I do not think I've tested that scenario. So if anyone comes into this kind of scenario, do lmk if it creates a softlock)