
  1. Home
  2.  » 
  3. Firm News
  4.  » San Marcos Marijuana DUI Defense Attorney. Marijuana Driving Under the Influence. Former Prosecutor explains Marijuana DUIs


Marijuana is legal in California.  As such, the use of marijuana has exploded here in San Diego.  With the increased use comes an increase in San Diego Marijuana DUI cases.  However, marijuana is different than alcohol.  These differences and lack of studies on marijuana use are the first steps in a San Diego Marijuana DUI.  Prior to opening his law firm, Attorney Mark Deniz was a deputy district attorney for almost 10 years with an intimate knowledge of the various consequences a DUI conviction may cause.  Mark Deniz will aggressively defend your case by exploring every angle and argument to ensure you have the best defense possible.  Contact the Law Offices of Mark Deniz at (858) 751-4384 to get the ball rolling.

What is the legal limit?

The issue is going to be how much is too much.  With alcohol, we know that .08% or greater will get you in trouble.  But how much is too much for marijuana?  That limit is likely to be determined soon.  In the meantime, it is going to be a combination of active marijuana in the system, coupled with impaired symptoms and bad driving.  Call the law offices of Mark Deniz for a consultation at (858) 751-4384.

People arrested for driving with marijuana in their system often pose no danger to the public, unlike drivers with alcohol and other drugs. Indeed, studies have shown that drivers that have ingested pot responsibly can drive safely, in some cases better than those who have not.  However, police and law enforcement, in general, believe that most people who smoke pot are “stoners” and potheads who deserve to be mistreated and are not worthy of a fair shake.  Moreover, California law does not allow police to confiscate a drivers license under the APS laws if the driver only has marijuana, no alcohol, submits to a test and is not a medical danger, however, many cops take the license anyway and serve a pink notice of suspension causing needless stress and inconvenience to the suspected impaired driver.

Astonishingly, many prosecutors continue to charge people with marijuana-related DUI in cases where the toxicology shows only THC metabolite.  With the passage in California of the legal use of recreational marijuana comes the concern that more drivers may decide to get behind the wheel after using pot.  In fact, AAA announced their concern that more needs to be done to understand when people are impaired by cannabinoids in order to enact legislation to establish per se levels of impairment similar to the .08 levels for alcohol.  In response to the new laws allowing for the recreational use of pot, many police departments and the CHP are ramping up their training of officers in the area of DUI enforcement involving drugs such as cannabis.  Call the Law Offices of Mark Deniz for a consultation at (858) 751-4384.

Why do I still have a Court case if the DMV set aside the arrest and suspension?  The DMV can only take action administratively under the APS laws if the driver has alcohol in their system or refuses to submit to a chemical test.  As long as you take a test and no alcohol is present the action initiated by the “pink piece of paper” will be set aside.  On marijuana DUI cases the DMV leaves it up to the Court case to determine if you will be suspended.  If you are convicted of VC 23152e the DMV will step in and suspend at that time.

San Diego DUI Defense attorney Mark L. Deniz knows the science and the law to win marijuana-related DUI cases in California.  If the lawyer you hire does not understand the scientific principles behind the testing and evidence collected you have little chance of winning.  A brief explanation of the terminology is as follows: Marijuana or Cannabis is “Delta-9-Tetraydrocannabinol” (THC).  THC is primarily metabolized to “11-hydroxy-THC” (THC-OH or OH) which is psychoactive or active.  The 11-Hydroxy-THC is then rapidly metabolized to the “11-nor-9-carboxy-THC” (THC-COOH, THC-A, or COOH) which is non-psychoactive or inactive, meaning your body is not being impaired either mentally or physically if only metabolite is present.  The DA or prosecutor most likely does not understand the biochemistry associated with the testing and will only see what he or she wants to see to convict you of driving under the influence, thus your attorney must be able to interpret the lab findings to beat the charges.  The law in California is clear: If the accused is not impaired by the drug he or she is not guilty of a San Diego Marijuana DUI.

Did you know that driving after ingesting marijuana is not necessarily illegal.  In fact, many folks who have been smoking pot earlier in the day and later get in their car and drive are not “impaired” to the degree necessary to be considered DUI, however, most cops are not properly trained to distinguish the guilty from the innocent.  Unlike alcohol, marijuana use is not subjected to “per se” laws that prohibit driving after reaching a certain level so the investigation and arrest are very subjective from officer to officer, this leads to injustice in many cases.  Call the Law Offices of Mark Deniz for a consultation at (858) 751-4384.

It is against the law to ingest cannabis to the degree you are impaired to drive, regardless of the reason you use it. Recently the state enacted Vehicle Code 23152(e) which makes it illegal to drive while under the influence of any drug.  But what does “under the influence” actually mean in the eyes of the law?  To be illegal the person first must be impaired to an “appreciable degree”, something more the simply showing signs of use.  The law requires the person be no longer able to drive with the same caption as someone that is completely sober.  There is no per se level of intoxication when it relates to a drug vs. alcohol.  Call the Law Offices of Mark Deniz for a consultation at (858) 751-4384.

San Diego Marijuana pot DUI Lawyer Mark Deniz is a former prosecutor who knows the scientific facts of Marijuana and driving: THC peaks rapidly in the first few minutes after inhalation, often to levels above 100 ng/mL in blood.  On the decline, it quickly comes down to single-digit levels within 1 hour.  High THC levels are therefore a good indication that the subject has smoked recently.  THC can remain at low levels, 1-2 ng/mL, for 8 hours without any measurable sign of impairment. Chronic users can stay at 2 ng/mL for 24-48 hours after ceasing use.

Why most cops get it wrong on the roadside when it comes to marijuana DUI impairment detection: First, most officers, depending on their training will misinterpret some or all of the symptoms of impairment allegedly caused by pot.  Notably, many officers will contribute bloodshot and watery eyes as being associated with a person being under the influence of cannabinoids.  However, the DRE studies all point to the conclusion that this symptom has NOTHING to do with impairment.  Moreover, the commonly reported symptom of “lack of convergence” is very often misunderstood by many officers because they fail to conduct the tests properly.  They do not adhere to the proper protocol and misjudge the distance from the bridge of the nose to the stimulus and therefore improperly conclude the suspect failed the test.  Further, the “rebound dilation” observations and “reaction to light” are almost always overstated in an effort to find the individual to be impaired.

Most chemical tests used by law enforcement may be flawed when it comes to determining levels of impairment.  Indeed, one of the more common tests administered to those arrested for drugged driving is the ruin test, however many scientists concur that this mode of testing is seriously flawed.  In one scientific study, it was revealed that urine tests do not detect the psychoactive component in marijuana, THC (delta-9-tetrahydrocannabinol) and therefore in no way measure impairment; rather they detect the non-psychoactive marijuana metabolite THC-COOH (Carboxy), which can linger in the body for days or weeks with no impairment effects.  Because of THC-COOH’s long elimination time, urine tests are more sensitive to marijuana than other commonly used drugs.

Driving under the influence of marijuana in San Diego is going to be perhaps the most overcharged crime because most police officers lack the training and experience to adequately determine the impairment of the drug.  With the passage of new laws, more and more folks are ingesting marijuana legally and the police are finding more ways to arrest them for possible DWI.  In San Diego, a DUI can occur one of two ways. The first is when a person has been consuming alcohol and is too impaired to drive or has a .08 % or more of alcohol in his blood. The second and far less common is when the individual has ingested some drugs such as marijuana and the ingestion of that marijuana has impaired the person’s ability to drive a motor vehicle.  No particular concentration of cannabis in the person’s blood is required, unlike that for alcohol.  Typically the police officer will testify to a variety of objective symptoms of impairment in order to justify the arrest and prosecution for “driving while stoned”.  Drug cases, and in particular marijuana, present a host of issues in the criminal case due to the lack of scientific correlation studies on impairment related to the operation of a motor vehicle. Call the Law Offices of Mark Deniz for a consultation at (858) 751-4384.

One of the more disturbing issues that have arisen in the last few years is that of passive inhalation of pot and the effects it has on a urine test.  In a recent study, volunteers were subjected to second-hand smoke in a small room and later they were tested for the presence of THC in their urine, it showed positive.  The standard test for a marijuana DUI is a urine test.  In San Diego, ordinarily, a person arrested for driving under the influence will be required to submit to either a breath or blood, however when drugs such as marijuana are suspected the choice is limited to blood or urine.  Because most people will choose to pee in a cup over having a sharp needle stuck in their arm, the most common test seen is that of urine.  Problems can come into play with marijuana urine tests.  The most often asked question is how long does marijuana stay detectable in a person’s urine?

It is fairly well accepted in the scientific community that marijuana metabolites (a breakdown product) is detectable in urine for an extended period of time compared to other drugs.  Initially, it is important to define what is meant by marijuana metabolites. Ordinarily, this term refers to a specific breakdown product of marijuana called delta-9-carboxy-tetrahydrocannabinol (otherwise known as THC). What is crucial to understand in the context of DUI prosecutions is that carboxy THC is not psychoactive and has no effect on ones physical performance or ability to drive an automobile safely.  Carboxy THC is an oily substance that accumulates in a person’s body fat over time after marijuana ingestion and is slowly released into the blood and excreted into the urine as a waste product.  This is the primary reason why carboxy THC is detectable in the urine for extended periods of time compared to that of other drugs and their metabolites.  Since the effects of marijuana seldom last beyond several hours, the presence of carboxy THC in the urine sample collected after an arrest for DUI does not necessarily prove that the individual was “under the influence” or impaired by the marijuana at the time of driving his or her motor vehicle.

How long the THC will stay in a person’s system and be detectable by a urine test depends on many different factors.  How frequent the person ingests marijuana, how sensitive the test is, and the recency of the consumption all come into play.  Recent scientific studies in the area have revealed that the smoking of a single marijuana cigarette can stay in a person’s system from one to sometimes three days. Other studies have shown that heavy smokers of marijuana (daily use for six months or more) can show positive for THC in their urine for up to two months after the last consumption.

To combat this problem the police, in recent years, have begun implementing DRE programs.  DRE stands for “Drug Recognition Examination” the process involves a multi-step approach of field evaluation.  The object of the DRE is to detect and identify specific drug impairment of the driver arrested for a DUI. Marijuana and other drugs are purported to be detectable using the process.  However, the examination is not as accurate as of the police claim and the DRE is often not performed in the correct manner.  The DRE evaluation takes about 30 to 40 minutes to perform correctly.  Although some Courts have ruled the procedure admissible in a criminal prosecution, many attorneys and legal scholars have argued the contrary.

One of the interesting nuances of a marijuana DUI vs. an alcohol-related drunk driving is that the DMV cannot suspend a person’s license under the APS laws.  What this means is that ordinarily when a police officer makes an arrest for VC 23152 he takes the driver’s CDL and issues a pink notice called an APS notice of suspension and temporary license.  However, marijuana does not trigger action under this law. In some cases, the officer may confiscate the license if a blood test was given and the alcohol results are unknown, in these cases a DMV hearing should be requested to challenge the case.  Call the Law Offices of Mark Deniz for a consultation at (858) 751-4384.


Marijuana can stay in a person’s system for one day and up to 2 months depending on the potency, and frequency of ingestion. However, since what is at issue in a DUI or driving under the influence prosecution is whether the person is at that time impaired by the drug, these factors can create significant defenses if handled by an experienced attorney familiar with this area of the law.  That attorney is Mark Deniz.  It is important to act quickly to obtain vital information necessary for a proper legal defense when charged with marijuana DUI.  For example, having the sample re-tested, making motions to exclude the test, challenging the constitutional aspects of the stop, and arrest are all possibilities in these cases.  An attorney is also crucial to ensure your license is not suspended by the DMV. Call the Law Offices of Mark Deniz for a consultation at (858) 751-4384.

FindLaw Network