When a professional driver is arrested for driving under the influence (DUI), the consequences reach far beyond ordinary court fines or short-term suspensions. For commercial driver’s license (CDL) holders in California, the stakes are existential: a second administrative finding or conviction within a ten-year window triggers a severe, long-term disqualification—often resulting in a career-ending loss of driving privileges.
Recently, nationally recognized DUI defense attorney Matthew Ruff exposed flawed evidence and secured a major victory at a California Department of Motor Vehicles (DMV) Administrative Per Se (APS) hearing for a commercial driver facing an imminent license revocation. By carefully dismantling the law enforcement officer’s report and employing scientific analysis, Mr. Ruff proved that the state’s evidence failed to establish driving with an illegal blood alcohol concentration (BAC).
Here is a breakdown of how Top Tier DUI Attorney Matthew Ruff dismantled the DMV’s case and protected a commercial driver’s livelihood.
The Backstory: High Stakes & Flawed Evidence
The driver was contacted by law enforcement in San Luis Obispo County following an alleged off-road vehicle infraction. The arresting officer noted basic objective symptoms, completed a single standardized field sobriety test (SFST), and administered subsequent breath tests yielding BAC results of 0.08% and 0.09%.
Because this was the driver’s second DUI allegation within ten years, a DMV finding against him meant a minimum two-year to lifetime administrative revocation—effectively putting an end to his commercial driving career.
To the untrained eye, two breath tests at or above 0.08% look like an open-and-shut case. However, veteran DUI lawyers like Matthew Ruff know that administrative forms—specifically the officer’s DS 367 statement—frequently contain serious evidentiary flaws, questionable field sobriety observations, and timeline inconsistencies.
Strategic Defense: How Matthew Ruff Dismantled the Case
Rather than relying on client testimony—which can carry risk when conflicting officer statements exist—Attorney Matthew Ruff utilized the department’s own evidence to exonerate his client.
1. Exposing Inadequate Field Sobriety Testing & Lack of Impairment
A key pillar of any DUI arrest is establishing reasonable cause that the driver was impaired. Upon inspecting the officer’s sworn statement and notes, Mr. Ruff highlighted several critical flaws:
- Failure to Standardize the HGN Test: Horizontal Gaze Nystagmus (HGN) requires strict administration guidelines. The arresting officer made improper observations (such as incorrectly evaluating smooth pursuit and tracking pupils) while claiming to observe nystagmus in only one eye—an anomaly inconsistent with alcohol-induced impairment.
- Failing the “6-Clue” Threshold: Standardized HGN evaluation looks for up to six specific clues. Even generously interpreting the officer’s flawed report, the driver showed at most two clues out of six—which is legally and scientifically recognized as passing the test.
- Absence of Objective Symptoms: The officer’s sworn DS 367 form failed to document physical signs typically associated with alcohol impairment:
- Gait: Marked as not unsteady.
- Speech: Marked as not slurred.
- Cognitive Function: No confusion or slurring noted.
Without reliable field sobriety tests or clear physical indicators, the justification for the initial arrest and subsequent testing was severely compromised.
2. The Rising BAC Defense: Using Retrograde Extrapolation
The most compelling aspect of the defense involved calculating the client’s actual blood alcohol level at the precise time of driving. Matthew Ruff is a recognized expert in the defense of retrograde extrapolation, the technique of establishing BAC at the earlier time of driving.
Under California law, the DMV must establish what the driver’s BAC was while behind the wheel, not hours later at the station. In this case:
- Time of Driving/Stop: 15:08 (3:08 PM)
- First Chemical Test Result: 0.08% at 15:40 (3:40 PM)
- Second Chemical Test Result: 0.09% at 15:43 (3:43 PM)
Analyzing the Numbers
The chemical test printouts showed a steady increase in BAC over time (from 0.089% up to 0.091%). Because alcohol takes time to absorb into the bloodstream, a rising trend between successive tests indicates that the driver was in the absorption phase.
By calculating the rate of rise across the 32-minute gap between the initial traffic stop and the chemical tests, Mr. Ruff demonstrated that at 15:08 (the time of driving), the client’s BAC was approximately 0.06%—well below the 0.08% legal threshold for standard drivers and within legal limits.
Timeline & BAC Trajectory Analysis:
15:08 (Driving Observed) ——-> Estimated BAC: ~0.06% (LEGAL)
15:40 (Chemical Test 1) ——-> Recorded BAC: 0.08%
15:43 (Chemical Test 2) ——-> Recorded BAC: 0.09% (RISING BAC)
The Verdict: Suspension Set Aside
By holding the state to its burden of proof and leveraging forensic science, Matthew Ruff successfully proved that:
- The objective symptoms documented did not support a finding of alcohol impairment.
- The scientific evidence established a Rising BAC, placing the client below legal limits at the actual time of driving.
The DMV Hearing Officer ruled in favor of the defense, issuing a full Set-Aside of the administrative suspension/revocation. The driver’s commercial license was fully protected, preserving his career and driving record.
Why Top-Tier Defense Representation Matters
Commercial drivers face zero-tolerance environments where a single administrative oversight can destroy a livelihood. Cases involving rising blood alcohol levels, questionable officer observations, or strict Title 17 breath-testing procedures demand aggressive, knowledgeable legal representation.
Matthew Ruff is known as the scientific evidence “truth teller”. With over 30 years of experience fighting complex criminal and administrative DUI cases across California, attorney Matthew Ruff continues to demonstrate why challenging every piece of police evidence is the key to securing exceptional results.
