Of course this is a movie, this scene had to be dramatized, and VIKI was truthfully interested in protecting humanity, but you've got to think that there was an easier way to kill Detective Spooner than this. Seriously, an NS-5 would probably make a hell of a sniper. Just set up outside Spooner's building, quick headshot when he leaves in the morning, and the NS-5 assassin is a mile away from the scene of the crime in less than a minute. Or he jumps down to the street and blends in with all the other robots.