Well, if it's the cops ya never know. It could be a fire and their waking up homeowners for evacuation, could be pursuit of a felon which stopped 2 doors down from your house and your home is now within the search perimeter, they could be bringing news of a death in the family, or they could be seeing smoke emanating from your own home... who knows....
Great! Talk to the camera.
Cops are used to talking to Ring and Blink doorbell/camera units these days. But none of the situations you mention are unable to be taken care of (at least initially) by a camera with two way audio. No reason to answer the door in person until you have established who it is and why they’re there via your camera system.