While the Constitution explicitly forbids “unreasonable” searches and seizures, it doesn’t do much to explain exactly what “unreasonable” means. The result is thousands upon thousands of Court decisions trying to interpret that phrase. Pretty much everybody knows that police are supposed to have a warrant before they come into a home uninvited. While there are some notable exceptions to that rule, there is no question that the most robust privacy protections citizens hold are within the walls of the home, our proverbial castle. Much fewer people understand what the law requires for police to come onto the other areas of their property without a warrant.
The courts have used the term “curtilage” to describe areas of a person’s property that isn’t inside the home, but in which the owner’s privacy should still be respected. For instance, most people would agree that it’s not reasonable to expect everyone driving by to avert their eyes from whatever is happening on your front lawn if you live on a busy street. On the other hand, most people would likely agree that it is reasonable for you to expect that intruders won’t climb a tall wall to peer into your back yard. What society reasonably expects in terms of privacy is the central consideration for a court when determining whether police have invaded your privacy without a warrant, thereby violating the Constitution.
In general, Police are allowed to go anywhere on your property that anyone else who isn’t invited would be allowed to go. Since most people would be allowed to walk up to your front door and knock, the courts have consistently agreed that police should be allowed to do so too. If, in walking up to your front door to do a “knock-and-talk”, they happen to stumble across the not-so-secret garden of potted opium plants next to your welcome mat, a judge is going to be reluctant to rule that a warrant was required. On the other hand, if the police wander off the path to your front door to check out the side yard and find your illegal herb garden hidden behind a barricade of trash cans, a very different conclusion would likely be reached.
So what happens then, when someone bucks the cultural norm of neighborly good-will by conspicuously warning unexpected visitors that they aren’t welcome? In Tennessee, James Christensen posted conspicuous “No Trespassing” signs at the entrance of his driveway next to the street curb. Police, who were responding to a tip that the Christensen was cooking methamphetamine in his home, ignored the signs, walked up to the front door and knocked. They did not request or receive a search warrant. Once the front door was opened, the officers could see evidence of the suspected drug lab, which they seized. Christensen was later convicted of several felonies as a result.
According to the Tennessee Supreme Court, the no trespassing signs did not prohibit officers from approaching the front door without a warrant. Their (seemingly counterintuitive) reasoning was that normal citizens would likely interpret the signs to be countered by an unstated exception that would allow anyone to drive into the driveway and/or walk to the front door.
While Tennessee is one of the most recent jurisdictions to consider the impact of no trespassing signs on the warrant requirement, it follows a host of other jurisdictions where courts reached the opposite conclusion. State courts in Louisiana, Texas, North Dakota, Montana and Oregon have all held that officers who bypassed no trespassing signs without a search warrant violated the Constitution. The Ninth Circuit Federal District Court in San Diego ruled the same way. The Tenth Circuit reached the opposite conclusion, with a notable dissenting opinion being written by Neil Gorsuch, prior to his placement on the United States Supreme Court.
Arizona courts have yet to publish an opinion specifically on point where this issue was considered. Whether they would agree with the majority of jurisdictions where a warrant was required or the few who stated otherwise remains to be seen. In the meantime, police are allowed to go anywhere onto private property where people who are not invited would be allowed to go and even a no trespassing sign might do little to avoid unwanted police contact. However, posting no trespassing signs in a conspicuous place at the front of your property might just provide some added scrutiny to unwanted police contact and certainly doesn’t hurt for those wanting to keep people from intruding on their private property.