Marijuana DUI Charges in Las Vegas: NRS 484C.110 Guide

A patrol officer pulls someone over on the 215 Beltway near Summerlin just after midnight for a minor lane drift, smells marijuana in the car, and requests a blood draw at the station. The driver has a valid Nevada medical marijuana card, has not smoked in more than a day, and does not feel impaired — yet the blood test comes back over the legal limit, and the driver is arrested anyway. Marijuana DUI charges in Las Vegas catch drivers off guard more often than almost any other kind of DUI arrest, because Nevada's law does not always require proof that a driver was actually impaired behind the wheel — in some cases, the state only has to show that THC was present in the driver's blood above a specific, and surprisingly easy to exceed, threshold. At Thomas Boley Attorney At Law, we defend clients throughout Las Vegas, Henderson, Summerlin, North Las Vegas, and the rest of Clark County who are facing a marijuana DUI charge after a traffic stop that turned into something far more serious than they expected.

Marijuana DUI Charges in Las Vegas: How Nevada Law Applies

Marijuana DUI charges in Las Vegas are prosecuted under the same general statute as alcohol-related DUI, NRS 484C.110, Nevada's core "driving under the influence" law. NRS 484C.110 makes it unlawful to drive or be in actual physical control of a vehicle while under the influence of a controlled substance, while impaired to a degree that renders a person incapable of driving safely, or — for a specific list of substances including marijuana — with an amount of that substance in the blood at or above a threshold set directly in the statute. Marijuana is treated differently than most illegal drugs on that list, because Nevada legalized recreational marijuana for adults 21 and older under NRS Chapter 453D in 2017, and the state has run a medical marijuana program even longer. That means officers throughout Las Vegas, Henderson, Summerlin, and North Las Vegas regularly encounter drivers who used marijuana legally, at a time when it was legal to do so, and are then arrested days later because THC or its metabolite is still detectable in a blood draw. Unlike an open container of alcohol, lawful marijuana use before driving does not, by itself, prove anything about how a person was actually functioning behind the wheel at the moment they were stopped — which is exactly the tension at the center of most marijuana DUI defense in Nevada.

Nevada's Per Se THC Limits Under NRS 484C.110

NRS 484C.110 sets a specific numeric threshold for marijuana: 2 nanograms per milliliter of blood for delta-9-tetrahydrocannabinol (THC), the compound responsible for marijuana's psychoactive effects, or 5 nanograms per milliliter of blood for 11-OH-tetrahydrocannabinol, the primary metabolite the body produces after THC is processed. Crucially, that per se threshold is not a blanket rule that applies to every marijuana DUI arrest in Las Vegas. By its own text, the threshold attaches to violations "punishable pursuant to paragraph (c) of subsection 1 of NRS 484C.400" — Nevada's felony third-offense DUI tier — as well as to DUI causing substantial bodily harm or death under NRS 484C.410, 484C.430, and 484C.440. For an ordinary first or second-offense marijuana DUI, the prosecution generally still has to prove the driver was actually impaired to a degree that made safe driving impossible, not simply that a blood test came back above the numeric threshold. That distinction matters enormously in practice: a frequent, lawful marijuana user can carry measurable THC and metabolite levels in their blood for days after their last use, long after any impairing effect has ended, which is why the numeric threshold is reserved for the more serious repeat-offense and injury-related charges rather than applied automatically to every stop.

Legal Marijuana Use Does Not Protect You From a DUI Charge

Nevada's recreational and medical marijuana laws regulate possession and use — they do not create any exception to the DUI statute. A valid medical marijuana card issued through the state does not prevent an arrest, and neither does buying marijuana legally from a licensed Las Vegas dispensary under NRS Chapter 453D. Officers throughout Clark County are trained to treat a marijuana DUI stop the same way they treat an alcohol DUI stop: observe driving behavior, look for physical signs associated with drug use, run standardized field sobriety tests, and, if there is probable cause, request a blood draw either voluntarily or under Nevada's implied consent law. The complication specific to marijuana is timing. Alcohol metabolizes at a predictable, well-studied rate that lets a blood test reasonably estimate impairment at the time of driving. THC does not behave the same way — it can spike quickly after use, drop just as quickly, and then leave a long tail of the metabolite detectable in blood well after any impairment has passed. A driver who used marijuana the night before, felt entirely normal, and was stopped for an unrelated equipment violation the next afternoon can still test positive — which is exactly the scenario where the impairment-based standard for first and second-offense charges, rather than a blanket per se rule, becomes the central issue in the case.

Penalties for a Marijuana DUI Conviction in Las Vegas

A marijuana DUI conviction in Las Vegas carries the same penalty structure as any other DUI under NRS 484C.400, because Nevada does not create a separate, lighter penalty scheme for drug-related DUI compared to alcohol. A first-offense conviction (within 7 years) is a misdemeanor punishable by 2 days to 6 months in jail (often served as a short weekend sentence or converted to 24 to 96 hours of community service), a fine of $400 to $1,000 plus court assessments that frequently push the real cost to $1,500 or more, a 185-day driver's license suspension, mandatory attendance at a Nevada-approved DUI school, a required victim impact panel, and — in most cases — an ignition interlock device for at least 185 days after reinstatement. Our guide to Nevada first-offense DUI penalties covers this tier in full detail. A second offense within seven years becomes a gross misdemeanor with mandatory jail time and a longer license revocation — see our guide to Nevada DUI second-offense penalties for the specifics. A third DUI within seven years, or a marijuana DUI that causes substantial bodily harm or death, becomes a category B felony under NRS 484C.400(1)(c) or NRS 484C.430, carrying state prison time — and this is the tier where the per se THC threshold described above can be used against a defendant without separate proof of impairment. Our guide to felony DUI causing injury or death in Nevada covers that tier and its prison exposure in depth.

Common Defenses to Marijuana DUI Charges

Because marijuana behaves so differently from alcohol in the body, a marijuana DUI charge in Las Vegas often has more genuine defenses available than people expect. The most significant is the impairment requirement itself: for a first or second-offense marijuana DUI, a blood test showing THC or its metabolite present is not automatically a conviction — the state generally still has to prove actual impairment, and a defense can attack that proof directly, including the timing gap between when marijuana was used and when the blood draw occurred. Field sobriety tests present another opening: the standardized battery used throughout Clark County was developed and validated specifically for alcohol impairment, and its reliability for marijuana is far less established, giving a defense attorney room to challenge how much weight a jury should give a failed test. The qualifications and methodology of any Drug Recognition Expert (DRE) who evaluated the driver can also be challenged, since DRE opinions rely heavily on subjective observations rather than a purely mechanical measurement. Testing procedure matters too — delays between the stop and the blood draw, chain-of-custody gaps at the lab, and calibration or storage issues with the sample can all undermine the state's numeric evidence. Finally, a valid medical marijuana card, while not a defense to impaired driving itself, can sometimes support an argument about tolerance and baseline THC levels that differ meaningfully from an occasional user's. Our overview of DUI defense and your rights during a traffic stop covers how these issues connect to the initial stop itself.

Speak With a Las Vegas Marijuana DUI Defense Attorney

Thomas Boley has represented clients throughout Clark County for more than 18 years, including drivers facing marijuana DUI, alcohol DUI, and combined-substance DUI charges arising from traffic stops across Las Vegas, Henderson, Summerlin, and North Las Vegas.

Call (702) 435-3333 for a free consultation, or contact Thomas Boley online to discuss a marijuana DUI arrest or a related criminal matter in Las Vegas, Henderson, Summerlin, North Las Vegas, or elsewhere in Clark County. Bring your citation, any blood-test paperwork, and your medical marijuana card if you have one. Our DUI defense practice handles every stage of a marijuana or drug DUI case, and our full criminal defense practice covers every related charge. This article is informational only and is not legal advice. Every case is unique.