The PBT (portable breath testing device) is commonly used by law enforcement officers to obtain a sample of someone’s breath to determine what BAC level he or she has. These portable devices are most often used during a traffic stop on the side of the road. A common question that arises is whether this reading is admissible as evidence or is it merely an investigative tool? Taking a sample of someone’s breath is considered a search and is protected by the 4th amendment. Thus in order for police to take a breath sample they must either obtain a warrant or fall within one of the exceptions to the warrant requirement.
The reasoning behind this that there is a high public interest in keeping intoxicated drivers off the road and that if the police spend time obtaining a warrant evidence of a person’s BAC will diminish. The time taken to get a warrant may take 2-3 hours and during that time alcohol in someone’s system is vanishing thus destroying evidence. Basically in NC as long as a police officer has reason to believe someone is driving intoxicated he may take a breath sample without violating the 4th amendment.
Although it is the PBT breath sample is a search that does not violate the 4th amendment when used to investigate DWI, it is generally inadmissible in a trial but may be admissible in the pre-trial.