This is an audio case brief of United States v. Dunn, 480 U.S. 291 (1987).The audio brief provides a full case analysis. However a written summary of the case is provided below.

Table of Contents


Ronald Dale Dunn and a codefendant, Robert Carpenter, were convicted by a jury of the following charges:

(a)Conspiring to manufacture phenylacetone and amphetamine,

(b)and to possess amphetamine with intent to distribute, in violation of 21 U.S.C. § 846

Dunn was also convicted of manufacturing these two controlled substances and possessing amphetamine with intent to distribute.

Here is the event that gave rise to Dunn’s  conviction.

In 1980 agents from the Drug Enforcement Administration (DEA) discovered that Carpenter had purchased large quantities of chemicals and equipment used in the manufacture of amphetamine and phenylacetone. DEA agents obtained warrants from a Texas state judge authorizing installation of miniature electronic transmitter tracking devices, or “beepers,” in some items that were ordered by Carpenter. Carpenter ordered an electric hot plate stirrer, a drum of acetic anhydride, and a container holding phenylacetic acid, which is a precursor to phenylacetone.

On September 3, 1980, Carpenter took possession of the electric hot plate stirrer, but the agents lost the signal from the “beeper” a few days later. The agents were able to track the “beeper” in the container of chemicals, however, from October 27, 1980, until November 5, 1980, when Carpenter’s pickup truck, which was carrying the container, arrived at Dunn’s ranch.

Aerial photographs of the ranch property showed Carpenter’s truck backed up to a barn behind the ranch house. The agents also began receiving transmission signals from the “beeper” in the hot plate stirrer that they had lost in early September and determined that the stirrer was on Dunn’s ranch property.

Dunn’s ranch comprised approximately 198 acres and was completely encircled by a perimeter fence. The property also contained several interior fences, constructed mainly of posts and multiple strands of barbed wire. The ranch residence was situated ½  a mile from a public road. A fence encircled the residence and a nearby small greenhouse. Two barns were located approximately 50 yards from this fence. The front of the larger of the two barns was enclosed by a wooden fence and had an open overhang. Locked, waist-high gates barred entry into the barn proper, and netting material stretched from the ceiling to the top of the wooden gates.

On the evening of November 5, 1980, law enforcement officials made a warrantless entry onto Dunn’s ranch property. A DEA agent accompanied by an officer from the Houston Police Department crossed over the perimeter fence and one interior fence. Standing approximately midway between the residence and the barns, the DEA agent smelled what he believed to be phenylacetic acid. The smell came from the direction of the barns. The officers approached the smaller of the barns by crossing over a barbed wire fence. He looked into the barn, and observed only empty boxes. The officers then proceeded to the larger barn by crossing another barbed wire fence as well as a wooden fence that enclosed the front portion of the barn. The officers walked under the barn’s overhang to the locked wooden gates and, shinned a flashlight through the netting on top of the gates to peer into the barn. They observed what the DEA agent thought to be a phenylacetone laboratory. The officers did not enter the barn. At this point the officers departed from respondent’s property, but entered it twice more on November 6 to confirm the presence of the phenylacetone laboratory.

On November 6, 1980, at 8:30 p.m., a Federal Magistrate issued a warrant authorizing a search of respondent’s ranch. DEA agents and state law enforcement officials executed the warrant on November 8, 1980. The officers arrested Dunn and seized chemicals and equipment, as well as bags of amphetamines they discovered in a closet in the ranch house.

The District Court denied Dunn’s motion to suppress all evidence seized pursuant to the warrant and respondent and Carpenter were convicted. But in 1992, the court of appeals reversed Dunn’s conviction. The Court of Appeals held that the barn lay within the house’s curtilage, and that the District Court should have suppressed certain evidence obtained as a result of law enforcement officials’ intrusion onto the area immediately surrounding the barn.

The U.S Supreme court granted certiorari to review the case.


The issue is whether the area near a barn, located approximately 50 yards from a fence surrounding a ranch house, is, for Fourth Amendment purposes, within the curtilage of the house.


The Fourth Amendment protects the curtilage of a house. And that the extent of the curtilage is determined by factors that bear upon whether an individual reasonably may expect that the area in question should be treated as the home itself. The central component of this inquiry is whether the area harbors the “intimate activity associated with the sanctity of a man’s home and the privacies of life.


In determining what constitutes a curtilage, the court outlined four factors:

  • The proximity of the area claimed to be curtilage to the home,
  • Whether the area is included within an enclosure surrounding the home,
  • The nature of the uses to which the area is put, and
  • The steps taken by the resident to protect the area from observation by people passing by.

And here is how the court applied these factors to the facts of this case:

First. The record discloses that the barn was located 50 yards from the fence surrounding the house and 60 yards from the house itself. Standing in isolation, this substantial distance supports no inference that the barn should be treated as an adjunct of the house.

Second. It is also significant that Dunn’s barn did not lie within the area surrounding the house that was enclosed by a fence. Viewing the physical layout of Dunn’s ranch in its entirety, it is plain that the fence surrounding the residence serves to demark a specific area of land immediately adjacent to the house that is readily identifiable as part and parcel of the house. Conversely, the barn—the front portion itself enclosed by a fence—and the area immediately surrounding it, stands out as a distinct portion of Dunn’s ranch, quite separate from the residence.

Third. It is especially significant that the law enforcement officials possessed objective data indicating that the barn was not being used for intimate activities of the home. The aerial photographs showed that the truck Carpenter had been driving that contained the container of phenylacetic acid was backed up to the barn, apparently, for the unloading of its contents. When on Dunn’s property, the officers’ suspicion was further directed toward the barn because of “a very strong odor” of phenylacetic acid. As the DEA agent approached the barn, he “could hear a motor running, like a pump motor of some sort….”. Furthermore, the officers detected an “extremely strong” odor of phenylacetic acid coming from a small crack in the wall of the barn. Finally, as the officers were standing in front of the barn, immediately prior to looking into its interior through the netting material, “the smell was very, very strong … and the officers could hear the motor running very loudly. When considered together, the above facts indicated to the officers that the use to which the barn was being put could not fairly be characterized as so associated with the activities and privacies of domestic life that the officers should have deemed the barn as part of Dunn’s home.

Fourth. Respondent did little to protect the barn area from observation by those standing in the open fields. Nothing in the record suggests that the various interior fences on Dunn’s property had any function other than that of the typical ranch fence; the fences were designed and constructed to corral livestock, not to prevent persons from observing what lay inside the enclosed areas.


The barn and the area around it lay outside the curtilage of the house, and accordingly the judgement of the court of appeals was reversed.

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