Breath tests are the most commonly used chemical test in DUI cases. They are preferred over blood or urine tests because they are quick, require no lab processing, and use equipment that is widely available to law enforcement.
In California, the implied consent law says a driver has agreed in advance to take a blood alcohol test if arrested for DUI. This agreement is a condition of driving on the state’s roads and applies to breath tests requested by law enforcement.
Refusing to take a breath test in California can result in significant penalties. A defense attorney for DUIs can provide guidance on your rights, explore the best strategies for your case, and explain everything you need to know about DUI breath tests.
What is a PAS Test, and Is it Different from a Regular Breath Test?
In DUI cases, law enforcement officers may use two types of breath tests: the Preliminary Alcohol Screening (PAS) test and the formal breath test. Here’s how they differ:
- A PAS test is typically conducted roadside, before an arrest, using a small portable breathalyzer machine to estimate your blood alcohol content (BAC). In most cases, you are allowed to refuse this test. However, refusal is not permitted if you are under 21 or on DUI probation.
- A formal breath test is given after an arrest at the police station and involves a more rigorous device designed for greater accuracy. Unlike the PAS test, it is illegal to refuse this test under California’s implied consent law.
PAS results are less reliable and more prone to officer error, which can make them easier to challenge in court. A skilled attorney can discredit a PAS breath test in a California DUI case by scrutinizing its accuracy, administration, and potential procedural errors.
How does a DUI Breath Test Work?
A DUI breath test measures alcohol consumption to estimate your blood alcohol content (BAC). The process involves multiple steps and must be conducted carefully by police officers to maintain accuracy.
Proper Training and Calibration
- Officers must be trained to use the portable breath testing equipment properly.
- Regular breath test calibration is essential to prevent inaccurate or skewed results.
Consent and Refusal
- After a DUI arrest, officers will inform you of your legal obligation to take the test and the penalties for refusal.
- Delaying or refusing can result in added penalties, such as increased jail time, longer license suspension, and mandatory DUI school.
Requesting Alternative Tests
- You may ask for a blood sample or urine test instead of a breath test. If these alternatives are unavailable, you must take the breath test.
Observation Period
- Officers must observe you for 15 minutes before administering the test to ensure you do not burp, vomit, eat, or drink anything that could contaminate the sample.
Administering the Test
- You’ll be asked to blow into the device for several seconds. If a medical condition, such as asthma, makes this difficult, inform the officers, and they should offer another test option.
Results and Limitations
- The device analyzes your breath and estimates your BAC. While the data is recorded, the breath sample itself is not stored and cannot be re-tested.
Understanding these steps can help you evaluate the accuracy of the test and address any procedural errors if you’re facing drunk driving charges.
Are DUI Breath Tests Reliable?
DUI breath tests are often inconsistent despite the science behind them being sound. Under ideal conditions, breath test machines can provide a reasonable estimate of your concentration of alcohol (BAC). However, real-world conditions frequently fall short, leading to unreliable results.
Common issues with breath tests include:
- The breath test machine wasn’t properly calibrated.
- Officers incorrectly stated that the roadside PAS test was mandatory, even though it’s optional.
- Drivers weren’t informed of the formal breath test requirement or the penalties for refusal.
- Delayed testing allowed BAC levels to rise naturally over time.
- The 15-minute observation period wasn’t followed.
- Operators mishandled or improperly used the equipment.
- Conditions such as GERD, diabetes, specific diets, or residual mouth alcohol caused inaccurate readings.
These issues can produce results that don’t reflect your true BAC. A faulty test could unfairly push you above the 0.08% “legal limit,” or even suggest impairment when you were sober. If your drunk driving arrest involved questionable breath test results, legal support can help identify errors and challenge the reliability of the evidence.
Can a Lawyer Challenge a DUI Breath Test?
Yes, a lawyer can challenge the validity of a DUI breath test by examining potential errors in the process. Attorneys can investigate whether the law enforcement agency followed proper procedures, including calibration of the breath test device and adherence to testing protocols.
Obtaining records like calibration logs, officer reports, and data from the test itself is essential for building a strong defense.
When Guidelines are Breached
If the test was not conducted correctly, such as failing to calibrate the device or mishandling the process, the court may suppress the test results. Without evidence of your blood alcohol level, prosecutors often face difficulty proving their case. This can result in reduced charges, like lowering a DUI to a lesser offense.
Unlawful Stops and Arrests
In some cases, a lawyer might uncover that the traffic stop or drunk driving arrest was unlawful. If this happens, the breath test results could become irrelevant. By identifying these issues, your attorney can help prevent a DUI conviction and protect your criminal record.
Why You need Legal Support for DUI Breath Tests
Understanding DUI breath tests and their legal implications can be challenging, especially with California’s implied consent law, which says a driver has agreed in advance to take a blood alcohol test when arrested for DUI. Knowing your rights and how these tests work is key to building a strong defense.
At Los Angeles DUI Attorney, we connect you with lawyers who will have your back. These legal professionals can help challenge breath test results, examine whether proper procedures were followed, and identify any mistakes that could strengthen your case.
If you have questions about a DUI breath test or are facing charges, reach out to Los Angeles DUI Attorney. We’ll help you take the next steps with a team that’s ready to fight for you.
