Matthew J. Ruff Criminal Law Blog on Lawyers.com

What is the exclusionary rule?

Saturday, March 28, 2009 by Matthew J. Ruff

As a Los Angeles Criminal Attorney I am often asked to explain what happens if the police violate a person's 4th amendment rights and find evidence to use against them in Court. Due to frequent abuses and unconstitutional actions by law enforcement the Courts created a remedy banning the use of evidence gathered under such circumstances called suppression. The exclusionary rule requires that all evidence obtained by searches and seizures found to have been done in violation of the rights of an accused are inadmissible against that person in a later criminal trial. The rule is premised on the notion that if private, constitutionally protected areas can be searched, and items taken unlawfully are used to obtain a conviction, the protections of the Fourth Amendment are of little, if any, value. The exclusionary rule is basically an enforcement mechanism, serving to give teeth to constitutional guarantees. Additionally, the rule bars the use of all forms of illegally obtained evidence. Physical evidence as well as statements can all be excluded, if they derive from an unconstitutional act, such as an unlawful arrest, illegal search or coercive interrogation. If law enforcement officials come by evidence through exploitation of their illegal conduct, the evidence is said to be tainted, and evidence tainted by illegal conduct on the part of police is inadmissible against an accused.

The exclusionary rule applies not only to the illegally obtained evidence itself, but also bars the use of evidence derived from the initially obtained illegal evidence, because of the initial illegality. This derivative, or secondary evidence, including an officers testimony based on knowledge garnered as a result of the illegal conduct, is often referred to as the fruit of the poisonous tree. To invoke the protection of the poisonous tree principle, the defendant must first demonstrate there was a primary illegality (i.e., an unconstitutional search or arrest, or a coerced confession), and secondly, a nexus, or connection, between the illegality and the derivative evidence. The nexus between the illegal act and the subject evidence must be so strong that police can be said to have obtained the evidence only by an exploitation of their illegal actions.

Posted at 19:59 PM

Topic: Criminal Law