Standard breathalyzer results often fail to hold up in court.
- Machines need exact calibration
- Officers must follow strict timing and observation rules
- Every test carries a known margin of error in testing
- Incomplete breathalyzer calibration logs or skipped steps make the readings unreliable
These all give a skilled defense real grounds to challenge them. A skilled DUI attorney knows exactly where to look for these weak spots from day one.
Real-world studies by G Simpson in the Journal of Analytical Toxicology show breath tests often differ from blood tests by more than 0.01 percent. Even when the machine works as designed, experts put the inherent margin of error around ±0.02. That gap can push a reading right at the legal limit of 0.08 into serious doubt.
Nevada law adds another layer: the machine must produce two consecutive samples that agree within 0.02, and the officer has to watch you for a full 15 minutes first.
Those gaps create real openings. Small mistakes pile up fast and open the door for a strong challenge long before trial.
Common Reasons Breathalyzer Results Fail in Court
The calibration process itself leaves plenty of room for error. Nevada requires a certified forensic analyst to test the machine against at least three different alcohol concentrations every 90 days. Even a single skipped step can destroy the presumption of accuracy.
Mouth alcohol is another frequent culprit. Residual alcohol can register as deep-lung alcohol from:
- A recent sip
- A burp
- Regurgitation
- Dental work
The machine cannot tell the difference.
- Certain foods and common medications also produce falsely high readings.
- GERD and acid reflux push alcohol vapors into the mouth long after drinking has stopped.
- Diabetes can create acetone that some devices misread as ethanol.
Rising blood alcohol concentration creates a different problem. Alcohol continues to be absorbed into the bloodstream for 30 to 90 minutes after the last drink. If the stop happened while you were still absorbing, the later test can show a number higher than what existed while you drove.
Nevada’s two-hour rule tries to limit this issue, yet officers sometimes test right at the edge of that window.
Operator mistakes compound everything. The officer may fail to restart the observation clock after a burp or ignore error messages like “interferent detect” or “slope not met.” Radio frequency interference from nearby electronics can also throw off the reading.
Any of these problems gives us solid grounds to file a motion to suppress.
What Is the Best Defense Against a DUI?
The strongest defense begins long before anyone talks about the breath number. A skilled DUI attorney first attacks the legality of the stop.
Officers need reasonable suspicion of a traffic violation or impairment before they can pull you over. Vague claims like “weaving within the lane” or “driving too carefully” often fail that test. When illegal traffic stop procedures occur, every piece of evidence that follows can be excluded, including:
- The breath result
- The field sobriety tests
- Any statements you made
We examine body-cam and dash-cam footage frame by frame.
- Did the officer actually watch you for the full 15 minutes without interruption?
- Was the breath-test operator certified at the time of the test?
- Did the machine produce two samples that truly agreed within 0.02?
Any break in protocol becomes a powerful suppression argument.
Field sobriety test validity often suffers at the same time. Officers sometimes treat a failed walk-and-turn or one-leg stand as automatic proof of impairment. In reality, uneven pavement or simple nerves can produce the same clues in a completely sober person.
NHTSA’s own laboratory data show the horizontal gaze nystagmus test is roughly 77% accurate under perfect conditions. Real roadside conditions lower those numbers further.
We highlight every environmental factor and physical limitation that could have affected performance. That creates reasonable doubt even if the breath result survives.
Can a DUI Be Dismissed in Nevada?
Complete dismissals happen more often than many people realize once the weak points surface. Courts in Nevada suppress breath results that violate:
- The dual-sample rule
- The 15-minute observation requirement
- The two-hour window
Police conduct defense and field sobriety test validity challenges often seal the deal. When the video shows the officer looking at a phone during the observation period, or when the roadside tests occurred on a steep shoulder in high heels, the entire case starts to unravel.
The key is speed. The sooner a DUI attorney reviews the file, the more leverage we have to force a favorable outcome.
Frequently Asked Questions
How Accurate Are Breathalyzers Compared To Blood Tests?
Breath machines convert breath alcohol into a blood-alcohol number using a fixed partition ratio of 2100:1. Real human ratios actually range from about 1500:1 to over 3000:1.
A lower personal ratio can produce a falsely high reading. Blood tests measure alcohol directly and skip this conversion step entirely. That is one big reason many people choose a blood draw when given the option.
What Happens If I Refuse a Breathalyzer Test in Nevada?
Refusal of an evidentiary breath or blood test triggers an automatic one-year driver’s license revocation for a first offense. A second refusal within seven years brings a three-year revocation. These administrative penalties apply even if the criminal DUI case is later dismissed.
Officers can still obtain a warrant and force a blood draw. Prosecutors may also argue the refusal shows consciousness of guilt.
Can I Request an Independent Chemical Test After a DUI Arrest?
Yes. Nevada law gives you the right to have a qualified person of your choice perform an independent blood or breath test at your own expense. The results can become powerful evidence if they differ from the police test.
Work With a Skilled DUI Attorney Who Knows How To Win
Breathalyzer results look powerful at first glance, yet they often collapse under careful review. When those weaknesses surface, charges get reduced or dismissed more often than most people expect.
An experienced DUI attorney can pull the full records and fight for the best possible outcome. At Benjamin Durham Law Firm, we have spent more than twenty years doing exactly that for clients across the Las Vegas and Henderson area.
Call us today for a free, confidential consultation. Video calls are available, and we speak Spanish. Let us put our experience to work for you and start building your defense right away.
