In California it is possible to be charged with a DUI for marijuana. However, unlike alcohol impairment, drugs are not absorbed and eliminated in a predictable manner to create a foreseeable pattern of behavior, which is why it is difficult to create a “per se” drug impairment level. As a result, researchers have concluded that we currently lack the data to establish a correlation with a specific drug concentration levels and “per se” drug impairment levels that should apply to DUID cases. Researchers have recognized that there is a paucity of objective data to support the creation of “per se” drug testing measures to support drug impairment claims in DUID cases.
In most DUID arrests the officer that makes the decision is called a Drug Recognition Expert (DRE). To determine whether a driver is under the influence of a specific category of drugs other than alcohol, DREs use a 12-step procedure based on a variety of observable signs and symptoms that are known to be reliable indicators of drug impairment. All DREs, regardless of agency, use the same procedures, in the same order, on all drivers. In theory, a DRE will not reach a final decision until the entire evaluation is complete.
The 12 steps of the DRE protocol that are required by NHTSA include the following:
(1) breath (or blood) alcohol concentration; (2) interview of the arresting officer; (3) preliminary examination; (4) eye examinations; (5) divided attention tests; (6) vital signs examination; (7) darkroom examination of pupil size; (8) examination of muscle tone; (9) examination of injection sites; (10) statements, interrogation; (11) opinion; (12) toxicology analysis.
A DRE’s opinion is based not on one element of the test, but on the totality of the evaluation. When in doubt, the DRE must find the driver is not under the influence.
If you have been arrested for Marijuana DUID, call the top DUI Lawyer for Marijuana, Matthew Ruff.
Since California legalized recreational cannabis, law enforcement agencies have ramped up patrols for Driving Under the Influence of Drugs (DUID). However, prosecuting a marijuana DUI is vastly different—and scientifically far more flawed—than prosecuting an alcohol-related offense.
California Cannabis DUID attorney Matthew Ruff has spent over three decades dissecting the police protocols, toxicological limits, and constitutional boundaries surrounding cannabis arrests. Here is a breakdown of how he builds strategic defenses to fight and win marijuana DUI cases.
1. Exposing the Flaws in Toxicological Testing
Unlike alcohol, which has a bright-line chemical threshold (0.08% BAC), California has no per se legal limit for cannabis.
- Inactive Metabolites vs. Active THC: Blood tests routinely detect THC-COOH—an inactive metabolite that can remain in a person’s bloodstream for days or weeks after use, long after any intoxicating effects have vanished.
- Retesting the Sample: Attorney Ruff frequently requests independent laboratory retests to evaluate whether the state’s toxicology report actually proves active Delta-9 THC impairment or merely traces of non-impairing historic use.
2. Challenging Police Officer Training & “DRE” Qualifications
Field sobriety tests (FSTs) were designed and validated specifically for alcohol, not marijuana. Police officers routinely misinterpret physical signs like eye redness or nervousness as proof of drug impairment. Level of Officer Training defense Strategy Standard Patrol Officer exposed for lacking specialized Drug Recognition Expert (DRE) training required to form a credible medical or scientific opinion. ARIDE Trained Cross-examined on official standards vs. shortcuts taken during field administration. Certified DRE tested on scientific literature to highlight inconsistencies between observed physical signs and known cannabis pharmacokinetics.
3. Suppressing Unlawful Interrogations (Miranda Violations)
Because chemical levels do not automatically prove impairment, prosecutors rely heavily on establishing a precise time of ingestion. Officers often conduct custodial interrogations asking when, where, and how much cannabis was used.
When police question a driver in custody without providing standard Miranda warnings, Matthew Ruff files targeted motions to suppress those statements. Stripping the prosecution of the alleged “time of use” often dismantles their entire timeline.
4. Attacking the Initial Traffic Stop (Fourth Amendment)
A marijuana DUI arrest is invalid if the initial contact was unconstitutional. Under Fourth Amendment jurisprudence, officers must possess objective, reasonable suspicion of a traffic violation or criminal activity to pull a vehicle over. If an officer acts on a vague hunch, attorney Ruff files a Motion to Suppress Evidence under California Penal Code 1538.5 to seek a full case dismissal.
Every cannabis DUI case rests on a unique combination of constitutional procedure and toxicology. Rather than settling for a guilty plea or a standard deal, a rigorous defense evaluates the science behind the arrest to hold law enforcement to the strict burden of proof.
Matthew Ruff is a Top Tier Torrance DUI Attorney with over 30 years experience fighting and winning DUID charges, including under 21 marijuana DUI charges within the state of California.
