The plain view doctrine allows law enforcement officials to seize and enter into evidence illegal property that is in their line of vision. It provides an opportunity for police to take items, even without having an official warrant. In order for an item to be considered in plain view, or in plain site, under the terms of the doctrine, the law enforcement official must not move anything and must be engaged in a lawful observation when the item is observed.
Under the Fourth Amendment to the United States Constitution, individuals are protected from unlawful search and seizure. This means police cannot search a person, his home, his car or any other property, without probable cause. The police must prove they have probable cause to a judge, who then issues a warrant, before conducting a search.
The plain view doctrine is an exception to these Fourth Amendment rights. The police are permitted under the Fourth Amendment to conduct casual observation and observation in public places. For example, the police are permitted to drive down the street and watch individuals who are standing on the corner. The police are also permitted to enter a person's living room if he invites them in or to pull a person over if the person is violating a traffic law.
When the police are engaging in the type of observation permitted by law, the police may notice unlawful or illegal activity taking place. They may also identify a weapon or something that has been used in a crime, such as stolen property. If the police can plainly see an item that is illegal or that has been used in the commission of illegal activity, the police can then seize that item under the plain view doctrine. The items taken under the plain view doctrine will be admissible in a court of law.
The police must have probable cause to believe that any item seized under the plain view doctrine is illegal or was used in the commission of a crime. The police cannot, for example, simply take a person's baseball bat if they see the person swing it in the park. If, however, the police hear about the robbery of a convenience store in which the clerk was hit with a baseball bat and then five minutes later see a man walking down the street with a bloody baseball bat, the police may seize the baseball bat as evidence; it was in plain site and there is probable cause to believe the bat was used in the commission of a crime. Likewise, if the police pull someone over for violating a traffic law and see drugs in the vehicle, the police may seize that evidence and use it against the driver as long as they did not have to move anything aside to see it.