The 4th Amendment to the U.S. Constitution places limits on the power of the police to make arrests, search people and their property, and seize objects and contraband (such as illegal drugs or weapons). These limits are the bedrock of search and seizure law. This article covers the basic issues that you should know, beginning with an overview of the 4th Amendment itself. (To read the 4th Amendment and other amendments in the Bill of Rights, check out Nolo's list of The Most Important Cases, Speeches, Laws & Documents in American History.)
The 4th Amendment: Protecting Your Privacy
The Fourth Amendment to the U.S. Constitution reads as follows:
"The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."
The search and seizure provisions of the Fourth Amendment are all about privacy. To honor this freedom, the Fourth Amendment protects against "unreasonable" searches and seizures by state or federal law enforcement authorities. (To read about NSA surveillance as exposed by Edward Snowden, see the blog post The NSA's Porn Problem.)
The flip side is that the Fourth Amendment does permit searches and seizures that are considered reasonable. In practice, this means that the police may override your privacy concerns and conduct a search of you, your home, barn, car, boat, office, personal or business documents, bank account records, trash barrel, or whatever, if:
- the police have probable cause to believe they can find evidence that you committed a crime, and a judge issues a search warrant, or
- the particular circumstances justify the search without a warrant first being issued.
Search warrants are discussed in detail in Search Warrants: What They Are and When They're Necessary.
When the 4th Amendment Doesn't Protect You
The Fourth Amendment applies to a search only if a person has a "legitimate expectation of privacy" in the place or thing searched. If not, the Fourth Amendment offers no protection because there are, by definition, no privacy issues.
Courts use a two-part test (fashioned by the U.S. Supreme Court) to determine whether, at the time of the search, a defendant had a legitimate expectation of privacy in the place or things searched:
- Did the person actually expect some degree of privacy?
- Is the person's expectation objectively reasonable -- that is, one that society is willing to recognize?
For example, a person who uses a public restroom expects not to be spied upon (the person has an expectation of privacy) and most people -- including judges and juries -- would consider that expectation to be reasonable (there is an objective expectation of privacy as well). Therefore, the installation of a hidden video camera by the police in a public restroom will be considered a "search" and would be subject to the Fourth Amendment's requirement of reasonableness.
On the other hand, when the police look for and find a weapon on the front seat of a car, it is not considered a search under the Fourth Amendment because it is very unlikely that the person would think that the front seat of the car is a private place (an expectation of privacy is unlikely), and even if the person did, society is not willing to extend the protections of privacy to that particular location (no objective expectation of privacy).
A good example of how this works comes from a U.S. Supreme Court case in which the court held that a bus passenger had a legitimate expectation of privacy in an opaque carry-on bag positioned in a luggage rack above the passenger's head, and that the physical probing by the police of the bag's exterior for evidence of contraband constituted a search subject to 4th Amendment limitations. (Bond v. U.S., 529 U.S. 334 (2000).)
What Happens When A Search Violates the 4th Amendment
The exclusionary rule. If, upon review, a court finds that an unreasonable search occurred, any evidence seized as a result of the search cannot be used as direct evidence against the defendant in a criminal prosecution, state or federal. This rule, established by the U.S. Supreme Court in 1961, has come to be known as the "exclusionary rule."
To this day, many commentators criticize the exclusionary rule on the ground that it unfairly "lets the criminal go free because the constable has erred." But the rule's supporters argue that excluding illegally seized evidence is necessary to deter police from conducting illegal searches. According to this deterrence argument, the police won't conduct improper searches if the resulting evidence can't be used to convict the defendant. (To learn about an important exception to the exclusionary rule, see Invalid Police Searches and the Good Faith Exception.)
Fruit of the poisonous tree doctrine. In addition to being excluded as evidence against the defendant, evidence resulting from an illegal search may not be used to discover other evidence, under a legal rule colorfully known as the "fruit of the poisonous tree" doctrine. The "tree" is the evidence that the police illegally seize in the first place; the "fruit" is the second-generation product of the illegally seized evidence. Both tree and fruit are inadmissible at trial. (See Fruit of the Poisonous Tree.)
Officer Wiley arrests Hy Lowe for selling phony telephone cards. A judge rules that Officer Wiley illegally entered Lowe's home and improperly seized a map showing the location where Lowe hid the phone cards. Officer Wiley then found the phone cards in that location. Because Officer Wiley obtained the map through an illegal search, the phone cards are the fruit of that unlawful search and are therefore inadmissible into evidence.
Some defendants believe that if they can show that a search was illegal, the case must be dismissed. Not true. If a prosecutor has enough other evidence to prove the defendant guilty, the case can continue. Also, the illegally-seized evidence can be:
- considered by a judge when deciding on an appropriate sentence following conviction
- admitted in civil cases and deportation cases, and
- in some circumstances, be used by a prosecutor to impeach (attack the credibility of) a witness who testifies in the trial.
To learn more about search and seizure law, get The Criminal Law Handbook: Know Your Rights, Survive the System, by Paul Bergman (Nolo). If you need to talk to a criminal defense attorney, you can turn to Nolo's trusted Lawyer Directory to find a lawyer near you.