A piece of evidence derived illegally: Fruit of the poisonous tree doctrine

“In most cases, evidence obtained by unlawful or illegal police activity is impermissible.”

 You may be aware that proof obtained by police during an unlawful investigation of you or your property is certainly impermissible in criminal court. You may also be aware that if officers abused your rights in extracting your claim, the prosecution is unlikely to be able to use it any further. For instance, by forcibly extracting it from you.

Besides, the prosecution cannot use proof derived specifically from police illegal activity, such as the statement or confiscated item. However, proof derived from the illegal activity the officers detected as a result of the statement or substance—is often impermissible or inadmissible. Precisely, the above is referred to as “fruit of the poisonous tree doctrine.”

A theme of several different versions

Although the United States Constitution has several important rights, each state has its own statutes and constitution. However, state law sometimes offers rights that are equivalent, if not equal, to those provided by the Federal Constitution.

The state law, on the other hand, occasionally grants additional rights. When learning about general criminal law principles, make sure to have this prospective extension in mind. It’s possible, for instance, the proof that may be permissible by the federal Constitution is not permissible by state law.

Moreover, proof obtained from almost every kind of police activity that breaches a defendant’s civil rights is considered the fruit of the poisonous tree doctrine. Ponder upon the case of an unauthorized wiretap.

Assume the police begin to hear in on and monitor alleged drug traffickers‘ comments without even obtaining a warrant. Now according to one of the sellers, he left some heroin in an empty factory for his customer to collect. Shortly after the cops enter the house and discover the heroin. Furthermore, the unlawfully registered statement (the poisonous tree) is impermissible, as are the drugs or heroin discovered by the police (the fruit of that tree).

A beneficial example

The prosecution incorporated drugs into proof in opposition to the defendant in Wong Sun v. US, a case that established the idea of the fruit of the poisonous tree doctrine. (371 United States 471 (1963).)

The narcotics were discovered by federal authorities from a witness they only heard of, because of a confession made by the suspect during illegal detention. According to the rule of the Supreme Court, all the things that the officers found as a part of the unlawful detention is considered the fruit of the poisonous tree doctrine: not only the statement alone but also the witness details they gathered from it, as well as the confirmed narcotics the witness directed them to.


The fruit of the poisonous tree doctrine principle has certain limitations, which means that any proof could be permissible even though it was obtained unlawfully. In cases where the government seeks evidence unlawfully but should have discovered it legitimately, courts use the words “attenuated taint” and “inevitable discovery.” 

However, the proof could be permissible in such cases. (See is unlawfully captured proof permissible to attack a defendant’s reputation, which is another way to get unlawfully acquired information into court.)

Imagine the example of wiretapping once more. The police receive a credible source who records the cocaine and its whereabouts, shortly after they go to the factory to steal the goods. Afterward, the informant’s tip, according to the court, may have given enough evidence for a legally obtained warrant to inspect the premises. The narcotics will almost certainly be accepted into custody in certain cases because the police most probably have identified without any of the unlawful wiretaps.  

You can consider one more example of the “attenuation doctrine.” It takes place where an officer doesn’t have a right excuse to detain someone but finds that the person being detained has a pending detention warrant. On the other hand, if the officer searches and arrests the suspect, then there is a good enough possibility that the officer’s findings will be permissible in court.

Statements of defendants

Defendants’ statements are another significant exception to the fruit of the poisonous tree doctrine. If police coerce a suspect into confessing, both the facts and the statements that resulted are impermissible. However, if the defendant confesses willingly, even if it is not accompanied by the necessary Miranda notice, the proof discovered by the police as a result of that statement will be used at trial. In the end, it doesn’t attain any value if the statement is impermissible – the poisonous fruit is still acceptable.

Contact an attorney

Fruit of the poisonous tree doctrine, like most legal rules, is complicated with exceptions and variations. It is always better to consult an expert criminal defense lawyer if you are caught up with any criminal charges. Just such a lawyer will properly protect and represent your interests.

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