We thought we should have a creepy soundtrack for our detectives entrance, then the music can pick up a bit when we see our damsel in distress running away from the kidnapper.
Some examples of this could be the into theme from 'Get Carter' or 'Dirty Harry'. Both of these themes start off creepy and give realism to the film. When the music crescendo's it kicks off the 'mood' and genre of the film. Both of these were crime thrillers, just like our film.