As the Detectives spot the Villain the soundtrack begins as they chase the villain and creates an intense chase.
During the detective scenes the soundtrack stops and the use of non-diegetic sounds of a confiscation creates both realism and also relieves the tension thats been built up, then as the scene ends the tension build up again as the villain spots another victim, as he walks up the stairs the use of non-digetic sounds of footsteps creates realism.