ntroducing a trained police dog to explore the area around the home in hopes of discovering incriminating evidence is something else. There is no customary invitation to do that. An invitation to engage in canine forensic investigation assuredly does not inhere in the very act of hanging a knocker. To find a visitor knocking on the door is routine (even if sometimes unwelcome); to spot that same visitor exploring the front path with a metal detector, or marching his bloodhound into the garden before saying hello and asking permission, would inspire most of us toâ€"well, call the police. The scope of a license â€" express or implied â€" is limited not only to a particular area but also to a specific purpose.
One question that arises from Jardines is whether the police can go up the front door when a homeowner puts up â€œno trespassingâ€ signs or something similar to indicate that this particular homeowner revokes the implied license. Do the signs revoke the implied license?
In United States v. Denim, 2013 WL 4591469 (E.D.Tenn. August 28, 2013), the district court (adopting the magistrate judgeâ€™s R&R) held that â€œno trespassing signsâ€ do not revoke the implied license and that officers can approach the front door and knock on the door despite the signs: