What Is the Nevada Two-Hour Rule for DUI?

For BAC chemical tests to be automatically admissible in a DUI case, Nevada law requires that police conduct the testing within two hours of a driver having physical control of the vehicle. For tests conducted after the deadline, the prosecution has the burden of proving admissibility. The rule may create significant opportunities for a DUI defense attorney to challenge a DUI charge.

Importance of the Two-Hour Rule

Under NRS 484C.110, chemical testing for BAC (blood alcohol concentration) related to a DUI stop must occur within two hours of driving in order for the evidence to be automatically admissible as direct evidence to prove the DUI violation. If testing occurs outside the two-hour window, the prosecution has a significant burden to prove the reliability of the evidence. The two-hour rule applies to BAC tests for alcohol concentration. It does not apply to tests for other illegal substances.

The two-hour timeframe begins when the driver last had actual physical control of the vehicle. In some cases, the beginning point of the window may be disputed. Many factors can be relevant, including the location of the vehicle key, the engine status (running or not), vehicle location, driver’s position (in the driver’s seat or elsewhere), and even whether the vehicle is capable of operating (e.g. flat tire, out of gas). All of these considerations may be evidence that relate to when the two-hour window was open.

The timing of a BAC test is important because it relates directly to the reliability of the results of the chemical tests. A driver’s BAC rises for about 30 to 90 minutes after the last alcohol consumption, so most people reach peak BAC after they stop drinking. The body eliminates alcohol at a specific rate per hour, and a person’s metabolism, body weight, and food intake affect the BAC rate. So, the test results may not reflect the BAC level at the time of the DUI stop, especially if significant time passed.

When testing occurs outside the two-hour window, test results are not automatically admissible in the DUI case. However, the prosecutor may introduce evidence to establish the reliability of the test results despite the delay, often including expert testimony, and must also provide a valid justification for the testing delay. This situation creates the opportunity for a knowledgeable DUI defense attorney to undermine the prosecution’s case.

If the test results are not admissible, the prosecution can still establish a case based on other evidence in the case.

Limitations of Relying on the Two-Hour Rule

Even if testing occurred outside the two-hour statutory window, a prosecutor can build a case with other evidence, such as police observations and video before and after the stop and field sobriety tests. The test results are only one element of the entire DUI case and are not essential to proving the violation. A DUI defense attorney must investigate the entire case and prepare a defense based on all of the evidence and circumstances, rather than relying solely on a failure to meet the two-hour requirement.

In addition, a DUI arrest may often involve other charges that are not affected by the two-hour rule, such as drug violations, reckless driving, or other traffic infractions that led to the stop. A DMV administrative hearing triggered by a DUI arrest is not affected by the two-hour requirement, either.

Defending Against a Nevada DUI Charge

In addition to defense strategies relating to the two-hour rule, DUI lawyers have a number of other tools and approaches to use in defending against a DUI charge.

The defense lawyer starts carefully reviewing the timing of BAC tests and procedures and may question chemical test evidence for reasons not relating to the two-hour rule, such as improper procedures and medical conditions. Field sobriety tests, which are unrelated to the chemical tests, also may be called into question due to test procedures.

Lack of probable cause for the stop is also an area of inquiry, as are statements made without proper Miranda warnings. A DUI defense lawyer’s role is to protect the driver’s rights at every stage and challenge evidence in every regard. Specific defenses may arise based on the circumstances, procedures, or the conduct of the investigation and case.

It is always critical to talk with a lawyer as early as possible when you face a DUI charge. Proceedings are time-sensitive and moving quickly can be very beneficial.

Schedule a Free Consultation With an Experienced Las Vegas DUI Defense Attorney

If you face a DUI charge in Las Vegas, attorney Joseph Gersten is here to help. He draws on his investigative background, criminal defense experience, and extensive trial background to provide an aggressive defense in every DUI case.

The Gersten Law Firm assists clients facing any state or federal criminal charge in Las Vegas, Henderson, and elsewhere in Clark County. There is no charge for your initial consultation. Call 702.857.8777 or complete our online form to schedule an appointment.