Prosecutor, actually. But you look like you'd do better as a defense lawyer.

[Does he really think that, or is Kokichi just wanting a friendly rivalry?]

Nothing's stopping you from continuing your detective work, though. The world could use more detectives right now. [Especially during the "Dark Age of the Law" when you can't exactly trust the lawyers to look for the truth instead of just trying to "win" cases. Not that Kokichi is planning on mentioning that right away.]