A toxicology report came back with a drug on it, and it can feel like the case is already decided. It is not. A drug DUI in Florida is different from an alcohol case in one decisive way: there is no per se limit. With alcohol, a 0.08 is a number the law treats as proof. With drugs, there is no such number, so the State has to prove that your normal faculties were impaired when you drove, not simply that a substance was in your system.
That gap between presence and impairment is the whole case, and closing it is harder than the State likes to admit. I am an ACS-CHAL Forensic Lawyer-Scientist, an NHTSA Standardized Field Sobriety Test instructor, and ARIDE trained, which means I work the drug recognition evaluation, the field exercises, and the lab toxicology from the inside. This page is the overview, and each issue opens into its own in-depth page, because a drug case is won in the details.
The One Question That Decides a Drug DUI
Florida Statute 316.193 makes it a crime to drive while your normal faculties are impaired by alcohol, by a chemical substance under section 877.111, or by a controlled substance under chapter 893. The 0.08 per se limit lives in a different part of the statute, and it applies only to blood or breath alcohol. There is no equivalent number for any drug. That means the case does not turn on what the lab found. It turns on whether the State can prove you were impaired, and presence in the blood or urine is not impairment.
Alcohol cases have a number the law treats as proof. Drug cases do not. With drugs, the State has to prove your faculties were impaired, not just that a substance was present.
Do not miss this
Refusing a lawful drug test can trigger an administrative license suspension on its own.
Even with no alcohol number in the case, refusing a lawful breath, blood, or urine test under Florida’s implied consent law can bring an administrative suspension under Florida Statute 322.2615, separate from the criminal case. You generally have only 10 days from the notice to demand a formal review hearing with the DHSMV. Acting early also lets us move to preserve any sample for independent testing.
Why this page is different
Most drug DUI pages just say the State has to prove impairment. This one shows how. I teach the field sobriety exercises that officers use, I have trained in the NHTSA drug recognition protocol that the State’s experts follow, and I read the gas chromatography and mass spectrometry data behind a drug result. This is a working resource, and each issue opens into its own in-depth page. See what the Lawyer-Scientist training covers.
Where a Drug DUI Is Won and Lost
A drug case has to clear four areas, and each one is a place where the State can fall short and the defense goes to work.
A drug DUI has to clear four areas. A weakness in any one can keep evidence out or take the case apart in front of a jury.
First, impairment itself. The State has to connect the drug to your actual driving, and presence, tolerance, and timing all cut against a simple story. Second, the drug recognition evaluation. The officer’s twelve-step opinion is built to confirm a suspicion, and its weak points are specific and well documented. Third, the testing. A urine result, an immunoassay screen, and a reported concentration each prove far less than they appear to. Fourth, the trial. A number on a page is not a person behind the wheel, and the field exercises were validated for alcohol, not for drugs.
The Four Areas We Attack
Why the Credentials Matter Here
Drug cases sit at the intersection of three things most defense lawyers handle from the outside: the field evaluation, the recognition protocol, and the lab. I work all three from the inside. As an NHTSA SFST instructor I teach the very exercises the officer used on you, and as an ARIDE-trained lawyer I know the drug-impairment material the State’s officers study. I have also completed a Drug Recognition Expert evaluation and trial-techniques course built on the NHTSA DRE curriculum, so I know the twelve-step protocol, the face sheet, and the drug symptomatology matrix the State’s expert relies on. My ACS-CHAL Forensic Lawyer-Scientist credential and chromatography training at Axion Analytical Labs mean I read the gas chromatography and mass spectrometry data behind a drug result the way the analyst does. Put together, that shows a court where the impairment opinion, the evaluation, and the number do not hold. See what the Lawyer-Scientist training covers.
Free guide
Free Guide: Drug DUI in Florida
No per se limit, presence versus impairment, and how drug DUI cases are proven and defended.
Drug DUI Questions We Hear Most
Is there a legal limit for drugs in Florida like the 0.08 for alcohol?
No. Florida's 0.08 per se limit applies only to blood or breath alcohol. For drugs, there is no number that proves the case by itself. Under Florida Statute 316.193, the State has to prove that your normal faculties were impaired by the drug while you were driving or in actual physical control. The presence of a substance in your blood or urine is not the same as impairment, and that gap is where a drug case is won.
I had a valid prescription. Can I still be charged with DUI?
Yes, a valid prescription is not a defense if the medication impaired your normal faculties, because Florida's DUI statute covers controlled substances under chapter 893 and chemical substances under section 877.111 taken lawfully or not. The flip side matters more: a therapeutic level of a prescribed drug, taken as directed, often does not impair a tolerant patient at all, and the State still has to prove impairment rather than mere presence.
Does a positive marijuana or THC test prove I was high when I drove?
No. THC and its inactive metabolite, carboxy-THC, can stay in the body for days or weeks after any effect has worn off, especially in regular users. A positive test shows past exposure, not impairment at the wheel, and there is no validated blood level that marks impairment the way 0.08 does for alcohol. The timing of use, the type of metabolite found, and the actual driving all matter far more than the number.
What is a DRE and do I have to do the 12-step evaluation?
A DRE is a Drug Recognition Expert, an officer trained in a 12-step evaluation meant to identify which of seven drug categories is causing impairment. The evaluation is voluntary. The protocol is built to confirm a suspicion the officer already has, it leans heavily on clinical signs that have innocent explanations, and its accuracy claims come largely from studies the police ran on themselves. We dissect the steps, the logs, and the training to show where the opinion does not hold.
Can the police make me give a urine sample?
Florida's implied consent law allows a urine test for drugs in some situations, and refusing has consequences for your license, but a urine result is one of the weakest forms of drug evidence. Urine shows that a drug or its breakdown product passed through the body at some point, not how much was active or whether you were impaired when you drove. We treat the demand, the collection, and what the result can truly prove as three separate questions.
The toxicology found a drug. Is my case over?
No. A drug result is a scientific claim, and it has to clear several checkpoints before a jury should rely on it. The screening test can produce false positives, the confirmation has to be done correctly, the concentration has to be interpreted fairly, and none of it answers the only question that matters, which is whether you were impaired when you drove. Reviewing the lab file and the evaluation is one of the first things I do.
Related pages: blood test defense, breath test defense, drugs and impairment in blood, and the main St. Petersburg DUI defense page.
This page is general information, not legal advice, and it does not create an attorney-client relationship. Drug DUI in Florida is governed by Fla. Stat. 316.193, section 877.111, and chapter 893, and chemical testing is governed by Fla. Stat. 316.1932 and 316.1933. Procedures and rules change, and every case turns on its own facts. Past results do not guarantee a similar outcome.
