Fleeting or evanescent evidence refers to evidence that is at risk of being destroyed or disappearing and cannot be easily recontructed through demonstrative evidence. Of course,destroying this evidence is a crime in and of itself known as spoilation of evidence. Evanescent evidence is mainly referred to in connection with warrantless searches; the term is usually stated as “the evanescent evidence exception to the warrant requirement.”

Usually, the police need a search warrant before they can seize evidence of a crime. However, under the evanescent or fleeting evidence exception, police can seize evidence without a warrant if the evidence poses a risk of being lost. The idea is that the evanescent must be seized immediately and therefore the police do not have time to secure a formal warrant. This is especially true if the suspect has made attempts to destroy evidence before a warrant is secured.

This is very similar to the idea of “hot pursuit” – that is, police also do not need an arrest warrant if the suspect has taken flight and they are in hot pursuit of the culprit.

What Are Some Examples of Evanescent Evidence?

There is no set definition for what constitutes evanescent evidence. In general it can include any item that needs to be obtained quickly before it is no longer available. Evanescent evidence generally refers to physical, tangible objects as opposed to verbal testimony. 

Some common examples of fleeting or evanescent evidence include:

  • Drugs or drug paraphernalia that may be discarded or destroyed (flushing drugs down a toilet is a common method of evasion)
  • Food that may spoil or rot, for use as evidence in food poisoning cases
  • Blood samples or blood marks that may evaporate
  • Delicate substances such as DNA, hair or skin samples
  • E-mails, text messages or other electronic files that can be deleted quickly

Bear in mind that oftentimes evanescent evidence has to do with the suspect’s motives in tampering with the evidence. Evidence is more likely to be classified as evanescent if the suspect has demonstrated an intention to destroy, conceal, or dispose of the evidence. Thus, even if the evidence is not subject to decay or destruction by its physical nature, it might be considered evanescent depending on how the suspect has treated it.   

What if the Police Have Illegally Seized My Property?

While police do not need a warrant to seize evanescent evidence, it is not rare for the police to make a mistake in identifying evidence. In order to proceed with a warrantless seizure, the police must have a reasonable belief that the evidence will be destroyed.   

If you have been subject to an illegal warrantless search or seizure, you would need to prove that the police made an unreasonable search in taking your property. The proper remedy in this situation would be for the judge to exclude the evidence during trial. The evidence will be suppressed under the exclusionary rule, meaning that the prosecutor cannot use the evidence against the defendant in court. 

Do I Need a Lawyer for Issues with Evanescent Evidence?

If you have been implicated in a crime, it is important to know all your rights, especially regarding the evidence that can be used in court. Evidence that is illegally obtained by the police cannot be used in court. You should contact a criminal defense lawyer immediately to discuss your rights if you have been subject to a questionable search or seizure.