Law Enforcement Tests Used in DWI Cases

Law enforcement officers must respect the constitutional rights of DWI suspects. Law enforcement officials typically ask DWI suspects to submit to one or more tests. These tests are intended to allow law enforcement officials to determine whether they believe a suspect is impaired. If you are a driver in North Carolina or you have been charged with a DWI, understanding the different DWI tests can be beneficial. When law enforcement officials do not properly administer DWI tests, they may result in improper findings.

If you are facing a DWI charge in North Carolina, our lawyers can help you fight the charge in an effective way. After speaking with you and evaluating the circumstances in your case, we can help you determine whether the law enforcement officers violated your constitutional rights. When officers obtain evidence in an unconstitutional way, a judge may throw out the evidence. A key defense in DWI cases involves actively determining whether the DWI testing that was administered was done so in the proper manner.

In order to stop a driver, law enforcement must have a reasonably articulable suspicion to do so. An example of a reasonably articulable suspicion would be a driver who is repeatedly swerving in and out of his lane. Law enforcement can ask defendant to perform standardized field sobriety tests. There are three standardize field sobriety tests. These include the horizontal gaze nystagmus test, the walk and turn test, and the one leg stand test. Suspects have a right to refuse to perform these field sobriety tests.

Unlike field sobriety tests, a suspect’s refuse to submit to a post-arrest breath test can result in a one-year driver’s license revocation. The results of a chemical test is often the strongest evidence that the prosecutors have to prove driving while impaired.

In order for the breath tests to be admissible in court, the testing must meet the administrative and statutory requirements. Chemical analyses are admissible in evidence to help prove impairment in a DWI case. A chemical analysis is a test of the suspect’s blood, breath, or other bodily fluid to determine the alcohol concentration or the presence of an impairing substance.

With respect to the intoxilyzer breath test, the evidence is only admissible if the prosecutor can demonstrate that it meets the following two conditions:

• ● Law enforcement conducted the breathalyzer test according to rules set forth with the Department of Health and Human Services, and
• ● The person who issued to analysis has a current permit to do so that specifically authorized that person to perform the test using that particular type of instrument

In order to be admissible in court, chemical testing must meet several requirements. First, the person conducting the test must observe the suspect. The tester must conclude that the suspect has not vomited, eaten, ingested any fluids, regurgitated, or smoked in the 15 minutes prior to collecting the breath sample. The tester may observe the suspect while he or she sets up the breathalyzer testing instrument.

North Carolina law enforcement officials do not always adequately maintain their breath testing instruments. The Department of Health and Human Services requires law enforcement officials to conduct preventative maintenance on their intoxilyzer machines at least once every four months. When the maintenance of the machines is questioned, courts often review the preventative maintenance records kept by the Department. Finally, testers must take at least two sequential breath samples when administering a breath test. In order to admit evidence from the sample, the two samples cannot vary by over .02.

Chemical test results are incredibly important because the test results are often the only evidence supporting a DWI conviction. When hiring a criminal defense lawyer, it is essential to hire attorneys who have an in-depth understanding of North Carolina’s chemical testing regulations. We scour the testing methods that law enforcement officials used when gathering evidence. If any inconsistencies or irregularities exist, we will petition the court to dismiss the case or throw out the improperly collected evidence.

If you are facing a DWI in North Carolina, time is of the essence. The more time to prepare an effective defense, the better. At Arnold & Smith, PLLC our lawyers have decades of experience fighting for the rights of our clients. Contact our Charlotte criminal DWI defense law firm today to learn how we can fight hard to protect your rights.