Final answer:
The "plain feel" doctrine allows an officer to seize items that are immediately recognizable as evidence or contraband during a lawful search, even when not in plain view. This doctrine works as an exception to the Fourth Amendment's requirement for a search warrant based on probable cause, as does the "plain view" doctrine and other scenarios like consent and exigent circumstances.
Step-by-step explanation:
The "plain feel" doctrine allows an officer to seize evidence other than contraband if it is immediately apparent to the officer that the items are evidence of a crime or are contraband while conducting a lawful search. This doctrine is an extension of the "plain view" doctrine, which allows an officer to seize evidence without a warrant if it is clearly visible, provided that the officer is lawfully present in the place where the evidence can be plainly seen and the officer has a lawful right of access to the object itself.
The "plain feel" doctrine specifically applies when an officer is conducting a legal frisk or "pat down" of a person for weapons and discovers items that while not immediately visible, can be felt and recognized as contraband or evidence of a crime. The key to the doctrine’s application is that the incriminating nature of the item must be immediately apparent upon touch.
It should be noted that the Fourth Amendment protects against unreasonable searches and seizures, and typically requires a warrant based on probable cause. However, doctrines like "plain feel" and "plain view" are exceptions that allow officers to seize evidence without a warrant under certain circumstances. Consent, exigent circumstances, and the aforementioned doctrines are situations where the expectation of privacy is reduced or negated, therefore allowing for warrantless searches and seizures if other legal conditions are met.