A search and seizure is a procedure that can be utilized by law enforcement when a crime has been committed to collect evidence and further the investigation. Many nations have specific protections to guard their citizens from “unreasonable” search and seizure, arguing that if the procedure is not administered properly, it can violate personal autonomy as well as privacy rights. The specifics of the law vary by nation and situation and people would be well advised to consult legal authorities in their areas to learn about the specifics of cases which may apply to them.
The first step in a search and seizure is the search. In the search, law enforcement officers search a clearly defined area, usually under the authorization of a warrant, looking for any materials which might be related to the crime. The second step is the seizure, in which items of interest are logged and removed for further examination. Warrantless searches are generally allowed when law enforcement have probable cause and/or someone is in immediate danger. For example, if a police officer is pursuing a suspect and the suspect enters a house, the officer can follow.
In a simple instance of a search and seizure, if law enforcement suspects that someone is involved in the production of child pornography, a warrant could be obtained for this person's home, garage, and storage area. Law enforcement personnel could search and remove computers, hard drives, storage, cameras, photographs, and any other materials which they believe could be utilized in the production and distribution of child pornography.
The definition of “unreasonable search and seizure” varies by nation. As a general rule, in a location where someone has a reasonable expectation of privacy, she or he is protected by law. The home is a classic example of an area in which privacy is respected. On the other hand, if someone has illegal materials on the front seat of a vehicle and a police officer spots them, this is not considered unreasonable, because there is no expectation of privacy for the front seat of a car.
Often, the defense attempts to exclude evidence from a case by filing a motion to suppress, and the motion can include in argument that the evidence was obtained illegally, and therefore cannot be used in court. Periodically, new legal precedents are set as judges explore the boundaries of the law when they rule on controversial search and seizure cases. These precedents, in turn, are used to set standards for the law enforcement community so that they know how to properly collect evidence.