Collecting as many notes and evidence as possible is crucial to solving the mystery. Once you think that you have it solved, make an accusation by going to the character that you want to accuse and by using the joystick, point to Talk to [character's name], and press the joystick button. Then point to Accuse [character's name] and press the joystick button. Depending on the amount of evidence collected, you will know if your hunch was right or wrong.