unreasonable search and seizure

Definition from Nolo’s Plain-English Law Dictionary

A search and seizure by a law enforcement officer without a search warrant and without probable cause to believe that evidence of a crime is present. Such a search or seizure is unconstitutional under the Fourth Amendment (applied to the states by the Fourteenth Amendment), and evidence obtained from the unlawful search may not be introduced in court. (See also: fruit of the poisonous tree)

Definition provided by Nolo’s Plain-English Law Dictionary.