[microgood]

A dog sniffing outside of a car is simply detecting an odor that has escaped the car. If the odor remained inside the car, the dog would never smell it. I would say that this is akin to a policeman at the front door of a house, seeing blood oozing out the door. Seeing that blood is not a search of the house, but the sight of that blood might provide the probable cause to search.

But if a policeman is at someone's door or has pulled someone over it is probably for another reason. If a dog is sniffing around a car, the entire reason the dog is there in the first place is to perform a search so it is disingenuous to say the dog is not searching since that is its sole purpose of its existence at the scene.

[NCLaw441]

The other reason requires not probable cause, but reasonable suspicion. Usually this is the result of a traffic stop...