Just to play devils advocate here is crime going down because of underreporting (either from smaller budgets or corruption to boost the image of a town / department)

What’s the source for this claim?

The ships biscuit experience, eat it below deck so you can’t see the weevils your eating

In the dark knight the police convoy encounters a roadblock (burning fire truck) and goes onto the lower road into an obvious ambush, rather than just… Go onto the incoming lane and around the truck