How the Intoxilyzer 9000 Is Used in DWI Cases

When a person is arrested on suspicion of DWI, the arresting officer may request that the individual submit to a breath test at the police station or jail. This is different from the portable breath test device used on the roadside, which is generally not admissible in court.

The Intoxilyzer 9000 is considered an evidentiary device. That means its results can be presented in court as part of the prosecution’s case. The machine records the BAC result, the time of the test, and other information such as the operator’s certification number and the device’s calibration status.

Legal BAC Limits in Texas

Texas law prohibits operating a motor vehicle with a BAC of 0.08 percent or higher. For commercial drivers, the limit is 0.04 percent. For drivers under the age of 21, Texas follows a zero tolerance policy, meaning any detectable amount of alcohol can lead to charges.

A result above the legal limit is often enough for the state to proceed with prosecution. However, the breath test result alone is not always accurate or reliable. It is just one piece of the puzzle.

Factors That Can Affect the Accuracy of the Intoxilyzer 9000

While the Intoxilyzer 9000 is a sophisticated device, it is not perfect. Several factors can cause false readings or affect the accuracy of the results. These include:

Operator Error

Only certified operators are allowed to administer breath tests using the Intoxilyzer 9000. If the person administering the test was not certified, failed to follow proper procedures, or did not observe the required waiting period before testing, the results may be challenged.

Improper Calibration or Maintenance

The machine must be regularly calibrated and maintained according to DPS guidelines. If maintenance logs show gaps, missed service dates, or failed tests, the reliability of the result may be questioned.

Medical Conditions

Certain medical conditions, such as GERD (gastroesophageal reflux disease), diabetes, or recent dental work, can cause the machine to detect alcohol from the mouth or stomach that is not truly reflective of blood alcohol concentration.

Mouth Alcohol

If a person recently consumed alcohol, used mouthwash, or vomited before the test, residual mouth alcohol may inflate the BAC reading. The operator is required to observe the subject for at least 15 minutes before administering the test to avoid this problem.

Rising BAC

Alcohol does not affect the body immediately. Your BAC may continue to rise for 30 to 90 minutes after your last drink. That means your BAC at the time of driving may have been lower than your BAC at the time of testing. The Intoxilyzer 9000 cannot account for this time delay.

Challenging Breath Test Results in Court

A failed breath test is not an automatic conviction. A skilled DWI defense attorney can challenge the validity of the Intoxilyzer 9000 results using several strategies. These include:

• Requesting the maintenance and calibration records for the machine
• Subpoenaing the operator’s certification and training records
• Reviewing video footage of the test to determine if the correct procedure was followed
• Consulting with experts in forensic toxicology or breath testing technology
• Filing motions to suppress the test results if your rights were violated

In some cases, we are able to show that the breath test result is unreliable or inadmissible. In others, we use these flaws to negotiate for reduced charges or to dismiss the case entirely.