officer could go up to the front door and knock and detect the smell of marijuana, just like officer pedraja did. >> well, then we've taken an unrealistic case, if that has been conceded, because it seems to me crucial that this officer went onto the portion of the house that -- as to which there is privacy, and -- and used a means of -- of discerning what was in the house that -- that should not have been available -- >> well, i think the way you would >> in that space. >> i think the way that you would answer that question, your honor, is, of course, there's a curtilage that extends around the house and protects, in which the homeowner has a reasonable expectation of privacy. it's well established, we think, going back to the common law, that there is an implied consent for people, visitors, salesmen, girl scouts, trick-or- treaters, to come up to your house and knock on the door >> yes, but not implied consent for the policeman to come up with the dog. the only purpose of the dog is to detect contraband. anyou can say, yes, there's implied invitation to the girl scout cookie seller, to th

we know they know that because they use mothballs, which officer pedraja found here at the front of the house, outside of the house. and so what you're talking about, although we talk about what's going on in the home, really what's happening here is odor of illegal contraband is being blown out into the street and someone is coming up to it and using their god-given senses in a way that humans and dogs have used for centuries and detecting that. >> well, we've had a lot of -- we've had a lot of discussion about whether it's 5 minutes or 15 minutes or whether it's mothballs. i understood the issue before us to be whether or not under the fourth amendment it is a search for a dog to come up to the door and sniff, not with respect to we're not making a judgment, i thought, on the probable cause in light of the totality of the circumstances, but the ground of decision below was this is a search when the dog sniffs. >> that you need probable cause just for the dog to sniff. no, that's absolutely right. and the dog sniff itself clearly is not a physical invasion in the same way that looking

we know they know that because they use mothballs, which officer pedraja found here at the front of the house, outside of the house. and so what you're talking about, although we talk about what's going on in the home, really what's happening here is odor of illegal contraband is being blown out into the street and someone is coming up to it and using their god-given senses in a way that humans and dogs have used for centuries and detecting that. >> well, we've had a lot of -- we've had a lot of discussion about whether it's 5 minutes or 15 minutes or whether it's mothballs. i understood the issue before us to be whether or not under the fourth amendment it is a search for a dog to come up to the door and sniff, not with respect to we're not making a judgment, i thought, on the probable cause in light of the totality of the circumstances, but the ground of decision below was this is a search when the dog sniffs. >> that you need probable cause just for the dog to sniff. no, that's absolutely right. and the dog sniff itself clearly is not a physical invasion in the same way that looking