The most important requirement for a warrantless search of a vehicle is that it must be based on the legal standard of probable cause that a crime related to the automobile has been or is being committed. Consent Searches Police officers may also undertake warrantless searches when the person in control of the area or object voluntarily consents to the search. Those who consent to such a search essentially waive their constitutional rights under the Fourth Amendment. Ordinarily courts are reluctant to accept such waivers and require the state to prove that the consent was actually given voluntarily. The plain-view doctrine is another exception to the general requirement of the need to have a valid search warrant to legitimize a search and seizure of a criminal suspect.
Curtilage refers to the enclosed area immediately surrounding a house or dwelling.
The use of wiretapping to intercept conversations between parties has significantly affected police investigative procedures. With approval from the court and a search warrant, law enforcement officers can place listening devices on telephones. The evidence collected is admissible and can be used in the defendant s trial. Law enforcement agencies also obtain criminal evidence through electronic communication devices, such as electronic mail, video surveillance, and computer transmissions. Arrest The power to arrest is used primarily by law enforcement officers.