Can Prosecutors Use Evidence from an Unlawful Search?
In general, no, a state prosecutor cannot use evidence that police obtained through an unlawful search. This principle is rooted in the exclusionary rule, which prohibits the use of evidence obtained in violation of the Fourth Amendment's protection against unreasonable searches and seizures. If police officers obtain evidence through an unlawful search—such as conducting a search without a valid warrant or probable cause—this evidence is typically considered "fruit of the poisonous tree" and must be excluded from trial.
The U.S. Supreme Court case Mapp v. Ohio, 367 U.S. 643 (1961), established that the exclusionary rule applies to state prosecutions, meaning state prosecutors are bound by the same constitutional limitations as federal prosecutors when it comes to using evidence obtained through illegal searches.
Background: The Exclusionary Rule
The exclusionary rule was first applied in federal cases by the Supreme Court in Weeks v. United States, 232 U.S. 383 (1914), which held that evidence obtained in violation of the Fourth Amendment could not be used in federal prosecutions. However, the question of whether this rule applied to state prosecutions was left unresolved until Mapp v. Ohio.
In Mapp, the Court extended the exclusionary rule to the states, holding that evidence obtained by state officials through an unlawful search could not be used in state criminal prosecutions. This decision was based on the principle of incorporation, which applies certain fundamental rights in the U.S. Constitution to the states through the Fourteenth Amendment.
The Facts of Mapp v. Ohio
In Mapp, police officers in Cleveland, Ohio, forcibly entered Dollree Mapp's home without a valid search warrant while investigating a bombing suspect. During the search, they found "lewd and lascivious" materials, which were used to convict Mapp under Ohio’s obscenity laws. Mapp argued that the evidence should be suppressed because it was obtained through an unconstitutional, warrantless search.
At the time, Ohio followed its own limited version of the exclusionary rule, which only barred evidence obtained through physical force or brutality. The Ohio courts upheld Mapp's conviction, but the U.S. Supreme Court ultimately reversed the decision, ruling that the exclusionary rule applied to state prosecutions under the Fourteenth Amendment.
The Supreme Court’s Ruling in Mapp v. Ohio
The Supreme Court held that the exclusionary rule applies to both federal and state prosecutions, meaning evidence obtained through an unlawful search by state or local law enforcement must be excluded from trial. The Court’s decision was based on the following principles:
Incorporation of the Fourth Amendment: The Court confirmed that the Fourth Amendment’s protection against unreasonable searches and seizures applies to the states through the Fourteenth Amendment’s Due Process Clause.
Deterring Unlawful Police Conduct: The primary purpose of the exclusionary rule is to deter police officers from violating constitutional rights by conducting unlawful searches. The rule prevents the government from benefiting from its own illegal conduct.
Fairness in Criminal Proceedings: Allowing illegally obtained evidence to be used in court would undermine the integrity of the judicial process. The Court stated that using such evidence “tends to destroy the entire system of constitutional restraints on which the liberties of the people rest.”
Exceptions to the Exclusionary Rule
While the exclusionary rule generally prohibits the use of unlawfully obtained evidence, there are exceptions where the evidence may still be admissible. These exceptions include:
Good Faith Exception:
If police officers conduct a search in good faith reliance on a search warrant that is later found to be invalid, the evidence may still be admissible. This exception was established in United States v. Leon, 468 U.S. 897 (1984). The rationale is that if officers acted reasonably and in reliance on a warrant, excluding the evidence would not serve the deterrent purpose of the exclusionary rule.Inevitable Discovery Doctrine:
Under this exception, if the police would have inevitably discovered the evidence through lawful means, it may still be admissible. This doctrine was established in Nix v. Williams, 467 U.S. 431 (1984), which held that the exclusionary rule does not apply if the evidence would have been discovered regardless of the unlawful search.Independent Source Doctrine:
If evidence is initially discovered through illegal means but is later obtained independently through lawful methods, it may be admissible. This exception allows evidence that was discovered unlawfully but later corroborated or obtained through legitimate means to be used in court.Attenuation Doctrine:
If the connection between the illegal search and the discovery of the evidence is sufficiently distant or "attenuated," the evidence may be admissible. This doctrine recognizes that, in some cases, the taint of the initial illegal action may be weakened or dissipated over time, particularly if intervening events occur.
How Defendants Challenge Illegally Obtained Evidence
If evidence has been obtained unlawfully, the defendant can file a motion to suppress the evidence, asking the court to exclude it from the trial. This motion typically argues that the evidence violates the Fourth Amendment’s protection against unreasonable searches and seizures. If the court grants the motion, the evidence will not be used in court, potentially weakening the prosecution’s case.
Significance of Mapp v. Ohio
The Mapp decision was a critical development in the protection of constitutional rights, as it ensured that the exclusionary rule applied uniformly across all states. It closed a loophole that had previously allowed states to use unlawfully obtained evidence in criminal prosecutions, even when federal prosecutors could not.
Before Mapp, states were free to establish their own rules regarding the admissibility of evidence obtained through illegal searches. This led to inconsistencies across the country, with some states allowing evidence that violated the Fourth Amendment to be used in prosecutions. Mapp established a uniform standard, ensuring that the Fourth Amendment’s protections apply equally in both state and federal courts.
Conclusion: The Exclusionary Rule in State Prosecutions
In summary, a state prosecutor cannot use evidence obtained through an unlawful search, as doing so would violate the Fourth Amendment. The exclusionary rule, established in Weeks and extended to state prosecutions in Mapp v. Ohio, requires that evidence obtained in violation of constitutional rights be excluded from trial. However, exceptions such as the good faith exception, inevitable discovery, independent source, and attenuation doctrines may allow unlawfully obtained evidence to be used in certain circumstances.
Frequently Asked Questions (FAQs)
What is the exclusionary rule?
The exclusionary rule prohibits the use of evidence obtained through illegal searches or seizures in court. It is designed to protect individuals' Fourth Amendment rights and deter unlawful police conduct.What happens if police conduct an unlawful search?
If police conduct an unlawful search, the defendant can file a motion to suppress the evidence. If the court agrees that the search violated the Fourth Amendment, the evidence will be excluded from trial.What is the good faith exception to the exclusionary rule?
The good faith exception allows evidence to be used in court if police officers relied on a search warrant they believed to be valid, even if the warrant is later found to be invalid.Can evidence be admitted if it was obtained unlawfully but would have been discovered anyway?
Yes, under the inevitable discovery doctrine, evidence may be admissible if the police would have inevitably discovered it through lawful means, even though it was initially obtained unlawfully.Does the exclusionary rule apply in state courts?
Yes, the exclusionary rule applies in state courts, as established by the Supreme Court in Mapp v. Ohio. Evidence obtained through unlawful searches or seizures by state law enforcement must be excluded from state criminal prosecutions.