Suppressing Evidence to Keep Your Trial Fair

If you have been charged with a crime, there are limits to what evidence the government can use against you. Any evidence that the police obtain through a violation of your Constitutional rights will not be allowed into court. There are two principles that courts rely on when considering evidence that was taken unconstitutionally: the exclusionary rule and the "fruit of the poisonous tree" doctrine.

Exclusionary Rule

The exclusionary rule is the principle that states that any evidence that is obtained by the police in violation of a person's Constitutional rights (usually the Fourth Amendment rights preventing unreasonable searches and seizures) may not be admissible in court. This rule is designed to protect people against government intrusion on their Constitutionally protected property.

A short example can illustrate this rule. Imagine that, one day, a man named Jim is driving his car and is pulled over by the police for texting while driving. The police officer then orders Jim out of the car and opens the trunk. In the trunk, the officer finds some illegal drugs.

Since the police officer had no reason to suspect that Jim had drugs in the car, and because he did not have a search warrant, the police officer had no right to search Jim's trunk. By searching the trunk, the officer violated Jim's Fourth Amendment rights, which protect against unreasonable searches or seizures. Since the drugs were seized unlawfully, the exclusionary rule means that the drugs would not be able to be used against Jim in court. The drug possession charges would likely be dismissed.

Fruit of the Poisonous Tree Doctrine

In the Supreme Court case Wong Sun v. United Statesthe Court held that any evidence, or "fruit," that the government finds as a result of an unconstitutional search or seizure will not be permitted to be used against anyone.

To illustrate this point, continue with Jim's example from above. Now assume that the police, before the drug charge can be dismissed, use the drugs found in the car to get a search warrant from a judge to search Jim's home for other drugs. Imagine that the police have no other evidence to show they need a warrant, and the judge does not know that the drugs were found by the police unconstitutionally. While searching the home, the police find large amounts of stolen jewelry.

According to the "fruit of the poisonous tree" doctrine, the jewelry would not be allowed in court because the only way the police found the jewelry was because of evidence they procured unconstitutionally. Even if the police had a valid search warrant, the warrant was only granted based on unconstitutionally found evidence. If the police did not ever find the drugs (which they shouldn't have), they would not have been able to find the stolen jewelry. Thus, since the police violated Jim's constitutional rights, the jewelry would be kept out of court.


If you think evidence against you has been taken unconstitutionally, you may be able to keep this evidence out of court by filing a motion to suppress it. Feel free to consult with an attorney to determine if this is the best course of action for you to take. You might consider speaking with a representative from Kirsten Swanson Atty for more information.