Strategie
The Basement Multiball and Penthouse are very lucrative. In the Basement you can just keep getting Jackpot after Jackpot. For the Penthouse it’s like printing money. Just keep making shots at the elevator. Keep making the shots consistently until the timer runs out (which is easy!) and it’s worth ~750M.
Do not necessarily choose the correct killer. For instance, if you have a number of clues it might be better to work on getting more clues (to light the extra ball) than to choose the right killer. Then you can start racking up more clues for the next extra ball.
Catch the killer! The 4 ball multiball (with ball saver for a bit) can be very lucrative
Etagen
Basement 3 ball multiball
Main Floor Light Slots and Roulette
2nd Floor 4 Taxi Letters (thus awarding a Clue) & lights the phone
3rd Floor Collect Evidence OR pick WhoDunnit
4th Floor Spin slot machine5th Floor Collect Evidence OR pick WhoDunnit
6th Floor Award a piece of equipment (furthest left, unlit one)
7th Floor Elevator Madness
8th Floor Interrogate a Suspect OR pick WhoDunnit
Penthouse Penthouse Party (accessible only after collecting the Penthouse Key)
Roof Catch the Killer