An extremely visual transformation.
An impossible prediction.
First you give the spectators the possibility to freely choose a card that after being remembered is returned to the deck.
You then give it to him to hold in his hands and show that you are wearing a security tape.
You mention that a murder has occurred here, we know the criminal but not the victim!
As a final blow we show him the security tape, we shake it and it magically transforms and tells us who the victim was.
The mystery is solved!