Law
Fact-checked

At MyLawQuestions, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is Fruit of the Poisonous Tree?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

The term "fruit of the poisonous tree" is used to describe a rule of evidence exclusion in the United States in which evidence obtained through illegal means is excluded from trial. The term references the idea that if the means — the "tree" — are illegal, then the evidence — the "fruit" — is tainted by association. This doctrine often comes up in the context of evidence associated with illegal searches and interrogations; even if the evidence itself is very solid proof of illegal activity, it is not considered admissible because it was obtained illegally.

Concerns about the fruit of the poisonous tree have led law enforcement agencies to train their representatives extensively in the protocols of evidence collection. No law enforcement agency wants to lose a case or have a case not go to trial because the evidence is not admissible. Law enforcement officers learn about how to collect evidence legally, and how to legally conduct searches, interrogations, and other activities to avoid uncovering and tainting evidence during illegal activities. On the flip side, citizens who educate themselves about the law can protect themselves from illegal law enforcement actions which may compromise their rights.

"Fruit of the poisonous tree" might be used in connection with an illegal interrogation.
"Fruit of the poisonous tree" might be used in connection with an illegal interrogation.

The United States Supreme Court hinted at this doctrine in the 1920 case Silverthorne Lumber Co. versus United States, in which the defendant argued that accounting information used in the case was seized illegally and was therefore not valid. This case set a precedent, laying the groundwork for additional cases and the eventual emergence of the term "fruit of the poisonous tree."

If a person's constitutional rights are violated in any way during an interrogation, then any evidence obtained during the interrogation is not permitted to be introduced in trial.
If a person's constitutional rights are violated in any way during an interrogation, then any evidence obtained during the interrogation is not permitted to be introduced in trial.

There are some cases in which evidence normally considered inadmissible under the fruit of the poisonous tree doctrine may be accepted by the court. The first case applies to evidence which would have been outed inevitably through legal means. The second case applies to evidence which is only weakly linked to an illegal action; if it can be demonstrated that the link is tenuous, the evidence may be allowed. Evidence is also allowed when it can be linked to independent and legal means of investigation.

The rules of evidence can be quite complicated.
The rules of evidence can be quite complicated.

The rules of evidence can get quite complicated, and lawyers often use this to their advantage when they work to get evidence suppressed or admitted. The fruit of the poisonous tree is one among several tools which a lawyer can use to try and argue that evidence should not be brought before the court. Since search and seizure are especially controversial in the United States, a lawyer who can successfully demonstrate that a search was illegal can often suppress the resulting evidence. If the bulk of a case rests on that evidence, it may be thrown out.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a MyLawQuestions researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a MyLawQuestions researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments

Terrificli

@Soulfox -- there are even exceptions when a private citizen swipes evidence and brings it to the police. If that citizen is acting in some capacity at the request of a police officer, for example, then the poisonous tree doctrine will probably apply.

Not to mention the private citizen in your scenario might also be guilty of a felony for breaking into a house.

Yes, the law is confusing...

Soulfox

There is a huge exception to this doctrine. It only applies to police officers, not private citizens. For example, if a policeman breaks into a house and steals the incriminating evidence that leads to an investigation of the home, then it is unlikely that any of that evidence will be admissible.

However, if a private citizen steals evidence, delivers it to the police and that triggers the investigation, the "fruit of the poisonous tree" doctrine probably won't apply.

Post your comments
Login:
Forgot password?
Register:
    • "Fruit of the poisonous tree" might be used in connection with an illegal interrogation.
      By: donserhio
      "Fruit of the poisonous tree" might be used in connection with an illegal interrogation.
    • If a person's constitutional rights are violated in any way during an interrogation, then any evidence obtained during the interrogation is not permitted to be introduced in trial.
      By: Steven Pepple
      If a person's constitutional rights are violated in any way during an interrogation, then any evidence obtained during the interrogation is not permitted to be introduced in trial.
    • The rules of evidence can be quite complicated.
      By: Leah-Anne Thompson
      The rules of evidence can be quite complicated.
    • Evidence gathered through illegal means may not be admissible in a court of law.
      By: aerogondo
      Evidence gathered through illegal means may not be admissible in a court of law.