Field Sobriety & Breathalyzer Tests

Feeling overwhelmed after a DUI arrest?

If you’ve recently been arrested for DUI, you may feel anxious, confused, or even hopeless. It’s common to assume there’s nothing you can do but accept your fate. But you have rights—and you have options.

Field sobriety and breathalyzer tests are not flawless. Mistakes can happen, and sometimes these errors lead to wrongful arrests. Police officers are trained to make judgment calls, but even experienced officers can make mistakes or misinterpret results. Machines can malfunction, and procedures can be mishandled.

How attorney John Thornton can help

With over 35 years of experience challenging DUI charges in Santa Cruz County, John W Thornton knows how to find weaknesses in the prosecution’s case. Our office understands the procedures police must follow and knows how to spot violations of your constitutional rights. We carefully review every detail, from the legality of the traffic stop to the accuracy of breathalyzer calibration.

You don’t have to face this alone. Many people don’t realize how much a skilled DUI defense lawyer can do to protect their future. We are committed to fighting for you, challenging questionable evidence, and ensuring your rights are respected.

What we do for you

  • Challenge field sobriety and breathalyzer results: We investigate whether tests were administered legally and accurately.

  • Review police procedures: We check if officers followed proper protocols and if your rights were violated.

  • Find holes in the case: We look for errors, inconsistencies, and evidence that can be disputed.

  • Reduce your risk of conviction: Our experience can significantly influence the outcome of your case.

Don’t wait—your future is important

Contact me now for a free, confidential consultation. Call 831‑426‑5800, or if you’d prefer email, I often respond on weekends and evenings.

  • Yes. A criminal defense lawyer can challenge the results of a field sobriety test and even dispute the findings of a Breathalyzer test. Police officers are trained to gauge how much motorists had to drink and whether their ability to drive safely was put at risk — some officers do this effectively, others do not. Breathalyzer and field sobriety tests are used to help police officers make important judgment calls — sometimes these are used properly, sometimes they are not.

    Field sobriety tests are not flawless and, sometimes, mistakes lead to unlawful arrests for DUI.

  • No. Most people take them because officers don’t always explain that they’re optional. Officers must have a valid reason to ask you to take these tests.

  • Breathalyzers are sensitive machines. If they’re not maintained or calibrated correctly, the results may not accurately reflect your blood alcohol content. We investigate maintenance records and challenge faulty results.

  • These tests mainly measure balance and multitasking ability—not intoxication. Poor performance can be due to anxiety, medical conditions, or other factors unrelated to alcohol.

  • Contact an experienced DUI defense attorney immediately. The sooner you get legal help, the better your chances of protecting your rights and your future.

Breathalyzer FAQs