If you're on the newest version, there is an unlock board. Go to Gallery, Unlock Board. There are "Challenges" you have to do to unlock the Tapes/Scenes.
But there is a tape for every death. That includes Nightclub deaths.
Alot of the unlock board things are pretty straightforward, it just requires a good eye. Some are stupid, and you'll get them from randomly clicking.
The one for Misty (Shark) that says something about grilled cheese is unlocked by clicking on an amulet in her fish tank. A loud humming with start to play, and you'll unlock the tape. The one about the orange lights is bugged right now, as I, and many other people cannot unlock it. The rest are easy. The ones about funny numbers are time-consuming, so I don't know if you'd want to unlock those.
As for an "Unlock All" Feature, that doesn't exist anymore. It used to be just pressing Numpad 8 on the main menu, but it seems they removed it.