16. The Police Had a Warrant to Search a Friend I Was Visiting, and They Searched Me as Well. Is This Legal?
No. Normally, the police can only search the person named in a warrant. Without probable cause, a police officer cannot search other persons who happen to be present at the scene of a search. However, if an officer has reason to suspect that an onlooker is also engaged in criminal activity, the officer might be able to "frisk" the onlooker for weapons. （See Section VI, below.）
17. If a Police Officer Knocks on My Door and Asks to Enter My Dwelling, Do I Have to Allow the Officer in Without First Seeing a Warrant?
Technically, no. A person can demand to see a warrant, and unless the officer has one can refuse the officer entry. However, people sometimes run into trouble when they "stand on their rights" and demand to see a warrant. A warrant is not always legally necessary, and a police officer may have information of which a person is unaware that allows the officer to conduct a warrantless search or make a warrantless arrest. People are right to ask to see a warrant. But if an officer announces an intention to go ahead without one, a person should not risk injury or a separate charge of "interfering with a police officer." A person should stand aside, let the officer proceed and allow a court to decide later whether the officer's actions were proper. At the same time, the person should make it clear that he or she does not consent to the search. If the police are not in a frenzied hurry, an individual might ask the police officer to sign a piece of paper acknowledging that "this search is conducted without the consent of . . . ." Otherwise, an individual might yell, "I do not consent to this search!" loud enough for others （potential witnesses if the matter comes before a judge） to overhear. （For more on consent searches, see Section III, below.）
"Knock and Notice" Laws
Statutes in some states require police officers searching pursuant to warrants to knock on suspects' doors and announce that they are police officers before breaking into a residence. However, such statutes are not constitutionally required; states need not require "knock and notice" in every instance. On the other hand, state laws may not authorize no-knock entries for a broad category of searches, such as searches involving drugs. （Richards v. Wisconsin, U.S. Sup. Ct. 1997; Wilson v. Arkansas, U.S. Sup. Ct. 1995.）