If you’ve been pulled over in South Carolina on suspicion of driving under the influence of marijuana, you’re likely facing a confusing and stressful situation. Unlike alcohol-related DUIs, where breathalyzers provide immediate results, marijuana impairment lacks a straightforward testing method.
In place of tests that yield immediate results, law enforcement officers are trained to rely on subjective observations—such as red eyes, erratic driving, or the smell of cannabis—and request blood or urine tests, which can detect THC long after its impairing effects have subsided.
With the above in mind, understanding the methods used to test for marijuana DUIs in South Carolina is crucial for protecting your rights. Knowledge about the limitations of current testing procedures, such as the absence of standardized field sobriety tests for marijuana and the challenges in correlating THC levels with impairment, can be pivotal in building a strong defense.
At Johnson, Johnson, Whittle, Lancer, and Staggs, we specialize in navigating the complexities of DUI cases involving marijuana. Our experienced Aiken DUI defense attorneys are committed to providing you with the guidance and representation you need during this challenging time.
If you’re facing a marijuana DUI charge, don’t navigate the legal system alone—contact us at (803) 649-5338 to schedule a consultation and learn how we can assist you.
Understanding Marijuana DUIs in South Carolina: What You Need to Know
As a criminal defense attorney here at Johnson, Johnson, Whittle, Lancer, and Staggs in Aiken, South Carolina, I often get questions from clients and members of the public about marijuana DUIs. The laws surrounding driving under the influence of marijuana can be confusing—and for good reason.
The science, procedures, and legal standards behind these cases are far less straightforward than those involving alcohol. If you’ve been pulled over or charged with a marijuana related DUI, it’s essential to know your rights, understand how these cases work, and, most importantly—know what you’re up against.
Let’s walk through it together.
Testing for Marijuana DUIs (And Why It’s Not Handled the Same Way as Alcohol DUIs)
In South Carolina, driving under the influence of alcohol, drugs, or a combination of both is a criminal offense under Section 56-5-2930(A) of the South Carolina Code. You can take a look at the law yourself here: SC Code Section 56-5-2930.
But here’s the catch: Testing for alcohol is easy. Officers use breathalyzers that give immediate, numerical results. When it comes to marijuana, however, the process is much less straightforward.
There is no breathalyzer for marijuana (at least, not just yet). Instead, law enforcement relies on a combination of field sobriety tests, officer observations (which, as you can imagine, can be subjective), and, in some cases, laboratory tests—usually urine or blood tests. However, each of these methods has some limitations that can complicate your case.
When you’re pulled over, the officer must establish probable cause to believe you’re under marijuana influence. With alcohol, a breath test can help build that case quickly. With marijuana, things aren’t so cut and dry.
Here’s what typically happens
The officer pulls you over for a traffic violation—maybe you were weaving, driving too slowly, or failing to use a turn signal. During the stop, the officer claims to observe signs that make them suspect marijuana use.
This could include:
- The smell of marijuana in the car
- Bloodshot or glassy eyes
- Unusual speech patterns
- Nervous behavior or anxiety
- Admissions of recent marijuana use
- The presence of marijuana or paraphernalia in the vehicle
In many cases, these observations are subjective. That means they’re open to interpretation—and challenge.
If the officer is ARIDE (Advanced Roadside Impaired Driving Enforcement) or DRE (Drug Recognition Expert) trained, they may try to conduct additional evaluations. These officers are trained to look for signs of drug impairment using a standardized 12-step process developed by the International Association of Chiefs of Police (https://www.theiacp.org/12-step-process).
The protocol is designed to provide law enforcement officers to understand the following:
- whether or not the driver suspected of DUI is indeed impaired; if so,
- whether the discovered impairment results from a medical condition or drugs; and if it results from drugs,
- what category and/or combination of categories of drugs are the cause of the impairment.
The Problem with THC Testing
Here’s another critical issue: Even if you agree to provide a blood or urine sample, testing positive for marijuana does not prove impairment at the time of the stop.
Let me explain.
THC—the active ingredient in marijuana—can stay in your system for days or even weeks, depending on how often you use it. That means you could test positive on a drug screen long after the effects have worn off. This is a key difference from alcohol, which clears your system quickly and has clearly defined impairment levels (.08 BAC, for example).
In other words, just because you test positive for THC doesn’t mean you were high when the officer pulled you over.
That’s a major weakness in the prosecution’s case—and a potential defense we can raise.
Field Sobriety Tests Aren’t Designed for Marijuana
Most officers will conduct standard field sobriety tests like the horizontal gaze nystagmus (eye test), walk-and-turn, and one-leg stand. But, these tests were designed to detect alcohol impairment, not drug use.
Marijuana affects people differently. Some users may not show obvious signs of impairment, while others might struggle with coordination or concentration even when they’re not high. The same physical symptoms used to justify arrest—like bloodshot eyes or delayed responses—can be caused by fatigue, allergies, anxiety, or even nervousness during a traffic stop.
This is another gray area in marijuana DUI cases—and one that an experienced defense attorney can challenge in court.
The Urine Screen Process in South Carolina
If the officer suspects marijuana use and you blow a 0.00 on the breath test, they may ask you to submit to a urine screen. Before they can do that, they are legally required to read and explain your implied consent rights to you, both orally and in writing.
You do have the right to refuse a urine test. But—and this is important—refusal comes with consequences. Under South Carolina law, refusing a urine or breath test can result in an automatic six-month suspension of your driver’s license. You do have the right to challenge that suspension at the Office of Motor Vehicle Hearings, but you must request a hearing within 30 days.
If you agree to the urine test, the officer will usually take you to a hospital. A nurse will ask you to provide a sample, package it, and hand it over to law enforcement. From there, the sample goes to the South Carolina Law Enforcement Division (SLED) for testing.
How We Fight These Charges of a Marijuana DUI
At Johnson, Johnson, Whittle, Lancer, and Staggs, if you are charged with a marijuana DUI, we dig into every part of your case. Was the traffic stop legal? Did the officer have probable cause? Were your rights explained properly? Was the field sobriety test administered correctly? Was the lab test accurate, and was the chain of custody maintained?
These are the kinds of questions we ask—and the weaknesses we exploit.
Keep in mind that, in order to convict you, the prosecution must prove beyond a reasonable doubt that you were impaired by marijuana at the time you were driving. That’s a high burden of proof, especially when the evidence is largely circumstantial and subjective.
What Happens If You’re Convicted of a Marijuana DUI?
A first-time marijuana DUI is typically a misdemeanor. But make no mistake—the penalties can be serious.
You could face:
- Jail time (up to 30 days for a first offense)
- Fines and court fees
- License suspension
- Mandatory drug and alcohol counseling
- Community service
- A permanent criminal record
If you have prior DUI convictions, the penalties increase significantly—including longer jail time, higher fines, and the possibility of being charged with a felony.
A conviction can also affect your ability to find work, apply for loans, or maintain a professional license. And if your case involved aggravating factors like driving with a child in the car or causing an accident, the consequences can be even more severe.
What You Should Do Next After Being Charged with a Marijuana DUI
If you’ve been charged with a marijuana DUI—or if you’re worried you might be—don’t wait. Your future, your license, and your record are all on line. These cases are complex, and the earlier we get involved, the more options we have to build a strong defense.
At Johnson, Johnson, Whittle, Lancer, and Staggs, we have the experience, resources, and local knowledge to fight these charges head-on. We’re not here to judge. We’re here to protect your rights and give you the best possible outcome.
Call us today at (803) 649-5338 to schedule a confidential consultation. We’ll listen to your side, explain your options, and help you take the next step forward.
We’re on your side—and we’re ready to fight for you.
