A controversial stop-and-search policy that allows a police officer to temporarily detain somebody and pat down the person's outer clothing when there are specific and articulable facts. Such facts only need to make a reasonable police officer to believe a person is armed and dangerous. The officer doesn't need to articulate or identify the specific crime he/she thinks is being committed, only that a set of factual circumstances exist that would lead a reasonable suspicion that criminal activity is occurring. Reasonable suspicion is one step below probable cause and one step above a hunch.

A frisk by definition is a type of search that requires a lawful stop. It is best thought of as a separate act, but in practice, a suspect who refuses to answer questions in a stop may be providing the officer with sufficient justification to frisk. A frisk should not be for anything other than a dangerous weapon or contraband. However, if other evidence, like a suspected drug container, is felt, it can be seized by the officer under the "plain feel" doctrine. The test for plain feel is that the item's contraband nature be "immediately apparent".

On August 12, 2013, NYPD's "stop and frisk" was ruled unconstitutional by U.S. District Judge Shira Scheindlin.