[immediately starts contemplating the problem, because no matter what you tell him, teacher's pet gonna try real hard]

Harukawa is the "Ultimate Assassin" — the titles are ridiculous, but seem to be based in reality as far as I can tell.

And Niska wants to be put on trial for murder... if she's a robot, it's because she wants to be recognized as a sentient being, I should think. So she'd have to have committed the act already.

The third... would that be you, Mr. Graham?