Using the exclusionary rule to block illegal evidence in criminal defense cases
In many criminal cases, it is important to consider potential Fourth Amendment issues when building a strong criminal defense. The Fourth Amendment, of course, deals with search and seizure requirements, and can be a critical component of criminal defense in cases where prosecutors rely on evidence which was obtained illegally.
When police officers do obtain evidence illegally, one of the remedies criminal defendants may have at their disposal is the so-called exclusionary rule, a judicially created rule which permits defendants to object to the admission at trial of evidence which was obtained as a result of Fourth Amendment violations.
The purpose of the exclusionary rule is to remedy the violation of the defendant’s privacy rights by not allowing prosecutors to benefit from evidence obtained as a result of an unreasonable search. Depending on the circumstances of the case, having illegally obtained evidence excluded from trial can sometimes significantly change a criminal case. This can happen in cases where the government’s strongest evidence supporting the charges was obtained illegally.
There are a number of exceptions to the exclusionary rule which limit its applicability. For example, a defendant is not able to have illegally obtained evidence excluded when the evidence could have been discovered by an independent source, when discovery of the evidence was inevitable, or when police acted on a good faith belief that they either had a valid warrant or did not need one at the time of the search.
In our next post, we’ll look at a case currently before the Supreme Court dealing with the limits of the exclusionary rule in cases involving a certain type of criminal investigative technique.