Summary Of Privacy, Probable Cause, And Reasonableness

Chapter 3 is titled "Basic Underlying Concepts: Privacy, Probable Cause, and Reasonableness." Privacy refers to an American citizen's expectation of privacy. Probable cause is usually needed by law enforcement officers before they can arrest an individual as well as search with or without a warrant. Reasonableness refers to the standard of searches and seizures to be valid under the Fourth Amendment. Katz v. United States (1967) is the case that demonstrated a change in the interpretation of the Fourth Amendment. Instead of a focus on protecting property, there is more of a focus on protecting privacy.
Probable cause to conduct a warrantless search is held to a higher standard of probable cause than it is for receiving a warrant to conduct a search. Probable cause is established through the collective knowledge of the police as a whole, as well as through individual officer knowledge and
These facts and circumstances include: flight, furtive conduct, real or physical evidence, admissions, false or implausible answers, presence at a crime scene or in a high crime area, association with other known criminals, and past criminal conduct. Information can also be obtained through officer training, knowledge, and experience in order to determine probable cause. However, an officer must be able to explain how their experience, training, and knowledge helped them to establish probable cause.
An informant is an individual that gives information to police officers on the criminal activity of others. Information that is obtained by law enforcement officers through the use of informants to establish probable cause is also known as the hear-say method. The key is whether the informant is credible and reliable. Their credibility needs to be "established by a statement of underlying facts and circumstances" (Ferdico, Fradella, & Totten