To what degree are dogs important in policing?

There seems to be a dearth of evidence about the effectiveness of dogs in tracking suspects and in police work in general, and I'm putting this on hn to push for better studies.

Nowhere in the article is the well-being of dogs mentioned, so that's another aspect I'm curious about. I grew up with dogs, I have trained dogs for "good citizenship", and I appreciate how much working dogs in particular have done for us. Dogs as companions feels like we're treating the symptoms rather than addressing the roots of our loneliness and other reasons for wanting a dog to care for.

They help generate probable cause for searches by responding to nonverbal cues from their handlers so that they "detect" contraband when it's desirable for them to do so.