When police officers in New Mexico and around the country perform warrantless searches without probable cause or obtain search warrants based on false or misleading information, the evidence they gather is likely to be ruled inadmissible in court. Judges may also exclude any evidence that is obtained as a result of the illegal search. The problematic search is known as the “poisonous tree,” and any evidence it gives rise to is considered “fruit of the poisonous tree.” This legal rule was created in 1920 when the U.S. Supreme Court ruled in the case Silverthorne Lumber Co. v. United States.

There are a number of exceptions to the fruit of the poisonous tree rule. This type of evidence is most commonly admitted when prosecutors are able to convince judges that police would have inevitably discovered it thorough other investigative means. Illegally obtained evidence may also be admitted when its connection to an illegal search is remote. In the eyes of the law, this kind of evidence is so attenuated that it is no longer tainted by the poisonous tree.

Another exception to the rule deals with evidence that is discovered during an illegal search and is then discovered again legally and independently. This is referred to as independent evidence. When prosecutors argue that excluded evidence should be considered independent evidence, they must convince judges that the original search and subsequent discovery are unconnected.

Experienced criminal law attorneys may mention legal doctrines like the fruit of the poisonous tree rule when they advise their clients about the rights of the accused. Individuals in police custody might feel that their situations are hopeless and cooperation is their only option, but attorneys may point out that the criminal justice system is designed primarily to protect the innocent rather than punish the guilty.