Unreasonable Search and Seizure
The 4th Amendment to the United States Constitution establishes the right to be free from "unreasonable searches and seizures". This doesn't, of course, mean freedom from all searches and seizures. Generally, law enforcement can search your home, property, car, financial records—just about any space or items over which you exercise control or which provide otherwise private information about you—in two situations.
Warrants
When the police have probable cause to believe that they'll find evidence of a crime, a judge can issue a search warrant allowing them to conduct a search under the terms and for the evidence specified in the warrant.
Warrantless Searches
Warrantless searches can be conducted under two different sets of circumstances.
No Reasonable Expectation of Privacy: A search warrant isn't required unless there is a reasonable expectation of privacy in the place or property being searched. For instance, if an item is lying in plain view on the front seat of a car, there is no reasonable expectation of privacy—anyone walking past the car is able to view the item. On the other hand, if the item is inside a zippered carrying case on the front seat of a car, there is—in most cases—a reasonable expectation of privacy in the case.
Having a reasonable expectation of privacy doesn't mean that police can't search—it simply means that they need a warrant, or a situation that falls into one of the exceptions, before they do.
However, where there is no reasonable expectation of privacy, the outcome is clear: searches are by definition not "unreasonable", and evidence, barring some other problem, is admissible.
For instance, courts have found that there is no reasonable expectation of privacy in information written on the outside of an envelope sent through the mail or left in an area accessible to others for mail pick-up, even when there might be a reasonable expectation of privacy in the contents. Other courts have established that there is no reasonable expectation of privacy in garbage set out at the curb for pick-up or taken to a dump, since a reasonable person knows that he is giving up control of the contents of that garbage and that they may be accessible to others.
Exceptions to the Warrant Requirement:
There are a number of exceptions to the warrant requirement, such as:
- CONSENT: Perhaps the most commonly applied exception to the warrant requirement is based on voluntary consent to the search. If the person having a reasonable expectation of privacy in the premises has voluntarily consented to a search, no warrant is required. In fact, probable cause is not required.
- Voluntariness: What constitutes voluntary consent is based on a "totality of the circumstances", meaning simply that the court will look at all factors surrounding the search in determining whether or not the consent was voluntary. There is no requirement, as there is regarding the right to remain silent, that police officers advise a person that he isn't required to consent to the search.
- Third Party Consent: In some cases, a person other than the defendant may consent to a search. For instance, courts have held that no warrant was required where one resident of property consented to a search, particularly when the spouse of the suspect, having an equal property interest in and control over the residence, has consented. There are qualifications on third party consent, though. For instance, a roommate may be able to give valid consent to search common areas like the living room and the kitchen, but may not be able to give valid consent to search the subject's bedroom.
- INVESTIGATORY STOP: Police harboring a "reasonable suspicion" that criminal activity is in progress or imminent may conduct a brief "seizure" and limited pat-down search/frisk for weapons. There is no definitive rule as to when this "brief seizure" becomes an arrest. In making that determination, courts generally consider the efforts made by the police to resolve their suspicions quickly and efficiently, the nature of the restraint on the person, and whether or not the person was transported to another location.
- SEARCH INCIDENT TO ARREST: When a person has been arrested, no warrant or consent is required to search the person in custody. In fact, no probable cause or even reasonable suspicion is required. So long as the arrest is valid and the timing and scope of the search reasonable, nothing further is required. Containers in the possession or control of the arrested person may be searched while in the subject's control, but once police have gained exclusive control over those containers, a search can no longer be classified as incident to arrest.
- EXIGENT CIRCUMSTANCES: Exigent circumstances simply means that quick action is required. For instance, if police reasonably believe that evidence is in imminent danger of being removed or destroyed, or if a danger still exists. For example, if a violent crime has occurred on the property and police have reasonable cause to believe that victims requiring assistance or dangerous persons are still on the premises, they may search immediately.
The circumstances under which police may be able to search without a warrant are varied, and often must be determined by courts on a case-by-case basis. If a search has already occurred and you are uncertain about its legality, talk to a criminal defense lawyer in your area right away.
The key thing to remember about search issues is that your consent will allow police to search in many circumstances under which they would not be able to obtain a warrant or search pursuant to one of these exceptions. In fact, criminal defendants are frequently convicted by evidence that would likely not have been discovered had they not consented to a warrantless search. Remember that the police have no obligation to inform you that you have the right to refuse a warrantless search, and the fact that you did not know you could refuse does not conclusively determine that your consent was invalid.