A DUI arrest can feel like the end of the road. The lights flash behind you, the officer asks you to step out of the vehicle, and before long you are facing charges that could affect your license, your record, and your future. But an arrest is not a conviction, and in California, the procedures law enforcement must follow during a DUI stop are detailed and specific. When officers fail to follow those procedures, it can create meaningful opportunities to challenge the charges against you — and in some cases, to have evidence suppressed or charges dismissed entirely.
If you were arrested for DUI in Aliso Viejo, CA, understanding your rights and the procedural requirements that apply to your case is one of the most important steps you can take.
The Stop Must Be Legally Justified
Every DUI case begins with a traffic stop, and that stop must be based on reasonable suspicion. This means the officer must have had an articulable, objective reason to pull you over — a traffic violation, a equipment issue with your vehicle, or observed driving behavior consistent with impairment. Officers cannot legally stop a vehicle based on a hunch, a general feeling, or factors that do not amount to reasonable suspicion.
If the initial stop was not legally justified, any evidence gathered as a result of that stop — including field sobriety test results, breathalyzer readings, and statements you made — may be subject to suppression under the Fourth Amendment. This is known as the exclusionary rule, and it exists precisely to deter unlawful police conduct.
Field Sobriety Tests Come with Their Own Rules
Field sobriety tests are standardized by the National Highway Traffic Safety Administration, and officers are trained to administer them in a specific way. The three most commonly used tests — the Horizontal Gaze Nystagmus test, the Walk-and-Turn test, and the One-Leg Stand test — each have defined protocols that must be followed for the results to be considered reliable.
If an officer administered a field sobriety test on uneven pavement, failed to give proper instructions, did not account for a medical condition or physical limitation that affects your balance or coordination, or scored the test incorrectly, those results can be challenged. An experienced DUI defense attorney will scrutinize every detail of how these tests were conducted.
Breathalyzer and Chemical Test Procedures Matter
Breathalyzer devices must be properly calibrated and maintained, and officers must follow specific protocols when administering breath tests. California law requires a 15-minute observation period before a breath test is administered to ensure the subject has not eaten, vomited, or regurgitated anything that could contaminate the sample. If that observation period was not properly conducted, the breath test result may be challenged.
For blood tests, the chain of custody — how the sample was collected, stored, labeled, and transported to the lab — must be carefully documented. Any break in that chain can raise questions about the integrity of the sample and the reliability of the results.
Miranda Rights and Statements Made During the Stop
If you were taken into custody and questioned without being informed of your Miranda rights, any statements you made during that questioning may be inadmissible. While Miranda violations do not automatically result in a case dismissal, they can significantly weaken the prosecution's case by removing key admissions from the evidence.
Law Office of Michael L. Fell Knows How to Find the Cracks in a DUI Case
Law Office of Michael L. Fell has extensive experience defending DUI cases throughout Aliso Viejo and Orange County. Attorney Fell approaches every case with a careful eye for procedural errors, constitutional violations, and evidentiary weaknesses that can be used to your advantage. Call (949) 585-9055 today to schedule a consultation and find out what defenses may be available in your case.