DUI cases are not won by arguing you were sober. They are won by finding what the police did wrong, and officers make mistakes at almost every DUI stop. I am Joel Brand, and here are the ones I look for first.
No legal basis for the stop
An officer needs reasonable suspicion to pull you over and probable cause to arrest. When either is missing, I can move to suppress everything that followed through a motion to suppress, which can end the case. This is the first thing I examine in every file, because the stop is the foundation the entire prosecution is built on. Officers frequently describe a "weave" or a "wide turn" that the dash-cam later shows was ordinary, lawful driving. If the stated reason for the stop was not actually a violation, the stop was unlawful, and the evidence that flowed from it, the observations, the field tests, the chemical result, can all be excluded.
Botched field sobriety tests
Officers routinely give the walk-and-turn, one-leg stand, and HGN tests incorrectly, on bad surfaces, with wrong instructions, which makes the results unreliable. See the unfair FST defense. These tests have standardized procedures for a reason, and when an officer deviates, the results lose their scientific validity. I look at whether the tests were given on a flat, dry, well-lit surface, whether the instructions matched the standardized script, and whether the officer accounted for age, weight, injuries, footwear, and medical conditions that affect performance. A nervous, sober person on the side of a freeway at night is set up to fail tests that were never as reliable as they sound.
Testing and observation errors
Skipping the required 15-minute observation before a breath test invites a mouth alcohol result, and ignoring calibration and maintenance rules undermines the number entirely. The breath machine is only as trustworthy as the procedures around it. I request the calibration logs, the maintenance records, and the observation timeline as a matter of course, because a gap in any of them can put the central piece of evidence in doubt. Blood cases have their own vulnerabilities: the qualifications of the person who drew the blood, the preservatives in the vial, the storage conditions, and the chain of custody all matter, and any break in them can be exploited.
Rising alcohol and the timing problem
One of the most overlooked mistakes is treating the test result as if it reflected the alcohol level at the time of driving. It often does not. Alcohol takes time to absorb, so a person's level can still be climbing for a while after the last drink. A test taken an hour or more after driving may show a number that was higher than the true level behind the wheel. Officers and prosecutors routinely ignore this, but the law cares about the level while driving, not at the station. Where the timeline supports it, this rising-alcohol argument can move a result below the legal limit.
Miranda and report errors
Custodial questioning without a Miranda warning, plus inconsistencies between the report and the video, give me leverage. See my top DUI defenses. When an officer interrogates a person who is in custody without the required warning, the statements can be suppressed. And the single most productive exercise in many cases is simply comparing the written report to the body-cam and dash-cam footage. Reports are often written at the end of a shift and describe what the officer expected to see; the video shows what actually happened. Every inconsistency between the two is a crack in the officer's credibility that I can use at the DMV hearing and at trial.
Prolonged detention and improper searches
Even a lawful stop can become unlawful if the officer drags it out beyond what the original reason justified, or conducts a search without a valid basis. A stop for a broken taillight does not automatically authorize a full DUI investigation unless the officer develops genuine, articulable suspicion of impairment along the way. Where the detention was prolonged on a hunch, or a blood draw was taken without a warrant or valid consent, those are additional grounds for suppression. I map out the timeline of the encounter to see exactly when, and on what basis, each new intrusion occurred.
Why these mistakes matter so much
A DUI case is unusual in that it is built almost entirely on what the officer did after the stop. There is rarely an independent witness; the case is the officer's observations, the officer's tests, and the officer's report. That makes the integrity of the officer's procedure the whole ballgame. When I find a real mistake, it does not just create doubt, it can remove the very evidence the prosecution needs. That is why my approach is to scrutinize the police work first and hardest, rather than trying to prove a negative about sobriety.
Checkpoint and procedural failures
When the stop came from a DUI checkpoint, a whole additional set of requirements applies, and officers do not always meet them. A lawful checkpoint requires supervisory officials to make the operational decisions, neutral criteria for which cars are stopped, a reasonable location and time, adequate warning signs and advance publicity, and only a brief detention. When any of those is missing, the checkpoint stop is vulnerable, and I obtain the operational plan and supervisory authorizations to test it. Beyond checkpoints, there are paperwork failures that matter too: incomplete admonitions before a chemical test, missing documentation of the observation period, and reports that contradict the timestamps on the video. Each procedural shortcut is a potential opening, and stacking several of them together often makes the difference between a case that resolves quietly and one that falls apart.
Why getting the records early matters
None of these mistakes can be exploited if the evidence that reveals them is lost. Body-cam and dash-cam footage, calibration logs, and dispatch recordings are not always preserved indefinitely, and some agencies overwrite recordings after a set period. Getting counsel involved quickly means the right preservation demands and records requests go out before anything disappears. I move early to lock down every recording and log, because the gap between the report and the actual footage is so often where a DUI case is won, and that gap only helps you if the footage still exists when we go looking for it.
Does this fit your case? Let's talk.
Whether this applies turns on the specific facts and records of your stop, which is exactly what I review. Use the free case analysis on this page, or call me directly at (888) 271-6644. I answer my own phone, 24/7.
From the DUI blog: What Not to Say to Police After a California DUI Stop.
From the DUI blog: What the Police Report Actually Says About Your DUI Arrest in California.
From the DUI blog: How to Get Police Body Camera Footage After a California DUI Arrest.