The U.S. Supreme Court has stated unequivocally that the Fourth Amendment demands that police officers who enter a dwelling -- with or without a search warrant -- must knock on the door and announce their identity and purpose before attempting forcible entry. Generally, exceptions to this rule come into play when knocking and announcing would be dangerous or futile, or if it would inhibit the investigation of a crime. In cases where an exception is asserted to justify a no-knock entry, the issue to be decided by a court is whether there were sufficient facts to support the exception. In the case at issue, the city police of Newport News (Virginia) had received information from an informant that a particular individual (Wooten) with a known history of violence and drug trafficking was using a specific house to store his drugs. Wooten lived elsewhere, but Grogins lived in the house where Wooten was alleged to keep his drugs. The informant further stated to police that Wooten was to be at Grogins' house on a specified night. Obtaining a warrant based on probable cause, a team of officers entered the house on that night without knocking and found Grogins in the house, but not Wooten. Drugs and drug paraphernalia were found in the house. The trial court ruled that the evidence obtained from the house had to be suppressed because of the officers' violation of the knock- and-announce rule. The Fourth Circuit Court of Appeals reversed the trial court in United States v. Grogins (1998), holding that the nature of drugs as easily disposable and the likelihood that a person known to be violent was present in the house justified the no-knock entry. The section of this report on drug identification summarizes information on the effects and identification of the following drugs: Ritalin, Dilaudid, Demerol, Schedule 3 drugs for the treatment of moderate pain, and three schedule 4 depressants.