The broad rules for what a “search”is are determined by whether a person has a privacy interest. Searches can be a physical search of items or a person, and can also be of conversations. Any evidence which could be considered incriminating can be discovered by a search, whether tangible or intangible. When a search is “reasonable” the evidence will be permitted in court. When a search is deemed unreasonable, the evidence will probably be excluded (there are exceptions to this rule).

The appropriateness of a search is determined by the nature of the privacy interest, the scope, conduct, and duration of the search. Therefore, beyond a few generalizations, the “reasonableness” of a search is an inquiry into the facts around the search.

I promised some broad generalizations. So here they are, but take them with a grain of salt. The law is filled with exceptions and that holds true for the rules for a reasonable search.

1. Generally privacy interests exist:

• Where a person has an expectation that his words or actions are private. (This includes the home or where conversations being held are otherwise intended to be kept private, such as a phone booth.)
• Where a person is invited or temporarily residing.

1. Generally privacy interests do not exist/ are lessened:

• Where and item is in plain view and the criminality of the item is immediately apparent.
• In public places holding a conversation which others could reasonably overhear.
• In registered vehicles on public highways or vehicles capable of moving on public highways (including RV’s).
• Where a police or peace officer’s safety is in question.
• At a person’s place of business has a lesser expectation of privacy
• In a field surrounding a home or in an area around a home which is in plain view from the street.

A search is generally reasonably begun in 2 situations: when there is a warrant for the search, and when there is probable cause and exigent circumstances allowing a peace officer to avoid getting a warrant.

1. A warrant requires an affidavit of probable cause (a sworn statement that shows why there is probable cause to believe criminal activity or criminal paraphernalia exists) and a precise description of the persons, places, and items to be search and what can be expected to be found. Having a warrant generally means the search will be reasonable.
2. Alternatively, a search can be reasonable at its inception when the is probable cause and exigent circumstances. Again probable cause refers to the probability that criminal activity is taking/has taken place and/or that criminal paraphernalia will be found on location. This probable cause must be combined with an exigent circumstance. There is a long list of court cited exigent circumstances, including officer safety, a need for immediate response to a situation, community safety, invitation to search, and others. The inquiry of reasonableness of this search is always fact based.

However, even a search that is “lawful at its inception can violate the Fourth Amendment if its execution unreasonably infringes interests protected by the Constitution.” (Illinois v. Caballes, United States Supreme Court) Therefore, even when there is a warrant or probable cause combined with exigent circumstances, if the search goes beyond a reasonable scope, duration or if conduct of the officers involved is unreasonable, then the search may not be reasonable.