United States v. Dunn, 480 U.S. 294 (1987), is a U.S. Supreme Court decision relating to the open fields doctrine limiting the Fourth Amendment of the U.S.

They did not enter the barn but stopped at the locked gate and shined a flashlight inside, observing what they took to be a drug laboratory.

The DEA arrested the respondent, seizing chemicals and equipment, as well as bags of amphetamines they discovered in the house.

However, the Court of Appeals reversed that decision, holding that the barn was within the residence's curtilage and therefore within the Fourth Amendment's protective ambit.

We do not suggest that combining these factors produces a finely tuned formula that, when mechanically applied, yields a "correct" answer to all extent-of-curtilage questions.