This mother and daughter attending the annual meeting of the National Rifle Association are enjoying the right to bear arms. This right is not absolute, however.hellerSearches and SeizuresPolice cannot arrest a citizen without reason. Before making an arrest, police need what the courts call probable cause, reasonable grounds to believe that someone is guilty of a crime.Police often need to get physical evidence—a car thief’s fingerprints, a snatched purse—to use in court. To prevent the abuse of police power, the Fourth Amendment forbids unreasonable search and seizure. It requires police to meet certain conditions.A search can occur if a court has issued a search warrant. Courts can issue a warrant only if there is probable cause to believe that a crime has occurredor is about to occur. A warrant, which must be in writing, has to specify the area to be searched and the material sought in the police search.A search can take place without a warrant (as most do) if probable cause of acrime exists, if the search is necessary to protect an officer’s safety, if the search is limited to material relevant to a suspected crime or within the suspect’s immediate control, or if there is a need to prevent the imminent destruction of evidence.81The Supreme Court has also held that police may enter a home without a warrant when they have an objectively reasonable basis for believing that an occupant is seriously injured or imminently threatened with serious injury.82The police can also use evidence after an illegal stop of a person if they conducted their search after learning that the person had a valid outstanding arrest warrant that was unconnected to the conduct that prompted the stop.83In various rulings, the Supreme Court has upheld a wide range of warrantlesssearches, including:aerial searches to secure key evidence in cases involving marijuana growing and environmental violations84breath tests of motorists85roadside checkpoints in which police randomly examine drivers for signs of intoxication86the use of narcotics-detecting dogs at a routine stop for speeding87the search of a passenger and car following a routine check of the car’sregistration88“hot pursuit” of criminal suspects89car stops90and “stop-and-frisk”91encounters with passengers and pedestrians when they are based on reasonable suspicion of criminal activity, rather than the higher standard of probable causemandatory drug testing of those in safety sensitive positions92and high school athletes,93even those who are not suspected of using drugs
the search of K–12 students with only a reasonable chance of finding evidence of wrongdoing, rather than probable cause94strip-searching anyone arrested for any offense before admitting them to jails, even if the officials do not suspect the presence of contraband95taking and analyzing a cheek swab of an arrestee’s DNA is, like fingerprinting and photographing, a legitimate police booking procedure.