The Rights of Search & Seizure
This right limits the power of government, not the actions of private citizens.
The fourth amendment does not not give citizens an absolute right to privacy, and it does not prohibit all searches— only those that are reasonable.
The courts have recognized certain situations in which warrantless searches are considered to be reasonable and allowed.
By law searches of private homes usually require a warrant, however the courts have made exceptions to certain cases in which searches without a warrant are reasonable
Search incident to a lawful arrest- a search that is part of a lawful arrest is considered reasonable, this allows the police to search a lawfully arrested person and the area around that person. They look for things like hidden weapons or for evidence that might be destroyed, this is known as a grab area search. The Supreme Court is allowed to do a “protective sweep” which is when they search for other potentially armed persons in an arrested person's home.
Stop and frisk- when a police officer is suspicious of a person and thinks they are armed, they may stop and frisk the suspect for weapons. This protects safety of both officers and bystanders so they don't get injured by a person that may be carrying a weapon.
Consent- When a person completely agrees to a search, the police can search without a warrant and without a cause. In normal cases a person grants permission for the police to search their own belongs however in certain situations people can give permission for the police to search other people's property.
Border and airport searches- It is part of custom agents jobs to search without warrants. They have to examine luggage before entering another country so danger is not brought in. They can only do body searches if there is suspicion of criminal activity. Here searches without warrants are permitted because it is mandatory for safety before entering a new country.
Vehicle searches- A police officer who has probable cause to believe that a vehicle contains illegal items may search the vehicle without a warrant. This does not mean the police have the right to stop and search vehicles randomly on the street. The right to search must be based on a probable cause.
Plain view- The police can search without a warrant if an object connected with a crime can be seen from a place where an officer has the right to be. If the police is able to enter a suspect's house and they see illegal items, they don't need a warrant to seize them.
Hot pursuit- If the suspect enters a building the police do not need a search warrant to enter the building as well.
Emergency situations- In certain situations the police is not required to have a search warrant. If it is in the heat of the moment like after a bomb threat, after smelling smoke or hearing screams they do not need a warrant. Sometimes getting a warrant can be a long process and evidence can be destroyed in that amount of time so they made exceptions to certain situations.