The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

No other Constitutional amendment has been used as often as the fourth amendment. The protection from unreasonable search and seizure is one of our most cherished rights. Nearly everyone is familiar with the term "search warrant" and have a basic understanding of what this term describes. A comprehensive definition is that upon finding probable cause (sufficient evidence exists that evidence in a crime is located in a specific place) the police or District Attorney (depending on where the crime is committed) will petition a judge for a search warrant. The police/DA must plead their case to the judge and provide sufficient evidence to show that the item(s) in question are located in the area to be searched. The judge, if he/she finds that this probable cause exists, then grants the police the right to search a specific area for either a specific item (murder weapon, document, body, etc.) or to search a specific area for any evidence of the crime under investigation. The term "specific area" can either be a vehicle, property, or subsection of a vehicle or property (i.e. dresser drawer, garage, vehicle trunk, closet, etc.). Once this search warrant is obtained, the police then present this warrant to the owner/occupant and conduct the search.

Certain exceptions exist which do not require a search warrant. These include: consent, plain view, open fields, curtilage, exigent circumstances, and motor vehicle exceptions, as well as others.

Consent is the simplest form of "warrantless searching" in which the police officer simply asks the owner of the vehicle/property for permission to conduct a search. If the owner/occupant gives verbal permission, then the search may be conducted within the restrictions given by the owner/occupant ("You can search everything but the glove box.")

Plain view seizures are just that. Objects in plain view of the public can be seized if they are lawfully deemed contraband or evidence in the commission of a crime (bomb on the dashboard or front seat of a car or a bag of money on the front seat of a bank robbery suspect's car).

Open fields are areas that do not have a "reasonable expectation of privacy" or are public property (city parks, national forests, pastures, etc.)

Curtilage is used to describe the area immediately outside a home or dwelling that the courts feel should be given the same protection as the home itself. However, courts have denied this protection based on the proximity from the primary dwelling, fencing, and the presence of certain types of plants and animals. Aerial surveillance is permitted of curtilage as long as the airspace over the curtilage is for "public use".

Exigent circumstances are ones in which no evidence is sought in connection with a previous crime, or those that endanger the life or property of others.

Example 1: A police officer is walking down the sidewalk and hears gunfire coming from inside a house. The officer may enter on the reasonable belief that someones life may be in danger.
Example 2: A police officer sees flames shooting from the window of a structure, enters and finds a meth lab. The meth lab can be used as evidence as the flames gave the passing police officer the reasonable belief that someones life or property may be in danger.

Motor vehicles have been deemed to have a lower expectation of privacy as they do not generally serve as primary dwellings or storage facilities of personal items. If during the execution of a traffic stop, the police officer notices a hand gun between the seats, it can be seized without the consent of the owner/occupant. Police officers may search areas that could conceal weapons or are within "arms reach" of the occupants of the vehicle. After establishing probable cause for a further search (weapons or drugs found in the vehicle) the police officers may search the entire vehicle, but not the passengers unless further probable cause is established (gun in the waistband).

Defense attorneys rely heavily on the interpretation of "reasonable expectation of privacy" when citing the fourth amendment. Often, the wording of the search warrant is vague enough to force the exclusion of evidence seized during the search. All evidence seized without a search warrant, and not meeting the above criteria for "exceptions" will be excluded from the prosecution's case.

The protection against unreasonable search and seizure is a luxury we cannot afford to lose. While a vast majority of Americans have nothing to hide from the police, the piece of mind that stems from this amendment is an invaluable commodity in our nation.