This article will briefly touch upon when a law enforcement officer, when placing someone under arrest, either inside their home or close to their home, may do what's called a "protective sweep," a term of art used in criminal law wherein an officer searches the interior of a home for other suspects or dangers. It is during protective sweeps when officers often find contraband or other evidence of an incriminating nature. However, there are only limited circumstances when the so called "protective sweep" can be implemented and, albeit often abused, the "sweep" can only be for very limited purposes.
A protective sweep, aimed at protecting the arresting officer, may be conducted only when the officer "possesses a reasonable belief based on specific articulable facts that the area to be swept harbors an individual posing a danger to those on the arrest scene." Maryland v. Buie, 494 U.S. 325 (1990). The purpose of the sweep when an arrest occurs is to check for possible accomplices, not evidence, and is justified only if necessary to allow officers to carry out the arrest without fear of violence. In Buie, the search/sweep occurred only after the suspect was outside his residence, handcuffed and unarmed. An officer must articulate or explain why he thought there was another person in the house.
If an individual is arrested, for instance, in the yard of his home, and no other evidence exists that there is another potential assailant inside the home, it is likely that if the officers enter the home to do a "protective sweep" and find incriminating evidence or contraband that such seizure is illegal and the evidence should be suppressed.