You base your views on what you see on TV? As many have said here, whether the lights and sirens get used depends on many factors, not least: time of day.
M
I meant those police programmes where they show real footage.
I remember one where it was in the countryside quite late, and the police showed up with sirens on and the guys who were burgling the house ran off. Now if they had gone there silent, they might not have been spooked?