After confiscating the chest and the shovel as evidence, she gets Frankie Fusilli to confess by making your sim wear a wire and calm him down, at which point he admits to money laundering and is taken away.
After his arrest, she comes back as a recurring hotel guest. After this, she has no further interaction with the storyline. She is also the last potential guest to be introduced into the game (excluding Ava Cadavra and Optimum Alfred), and also the only one to be introduced midway through gameplay.
Her secret is that her boss at the FBI hasn't actually told her why she is in Strangetown.