The Predator enters the urban jungle of Mega-City One to hunt a challenging prey – the Judges themselves. As the Judges' heads start accumulating in the Predator's trophy room, it is down to Dredd and Schaefer to stop the hunt.
When discussing the Predator, the Judges say it had visited New York. This never happened in the film but did in the Predator comic book story Concrete Jungle, written by Mark Verheiden (which parallels a lot of the themes in the second film).