If you were arrested for driving under the influence of a drug and never touched a drop of alcohol, you are not imagining how strange this feels. Maybe you took a medication your own doctor prescribed, exactly as the bottle said. Maybe you used lawful medical marijuana days earlier. Now a lab report has your name on it, and it feels like the case is already decided.
It is not. I’m Rory Safir. I was an Assistant Public Defender in Tampa, and I wrote a free guide, Drug DUI: Presence Is Not Impairment, about why these are among the most defensible cases in the whole field. Here are three things from it.
Three things from the guide
There is no number for drugs
With alcohol, the State has a shortcut: 0.08. For marijuana, THC, prescription medication, and other controlled substances, no per se limit exists in Florida. No number automatically proves a drug DUI, so the State must prove your normal faculties were truly impaired while driving, not merely that a substance was present. Florida courts drew this line long ago: in West v. State, 553 So. 2d 254 (Fla. 4th DCA 1989), the court held it was reversible error to put a mere trace of a drug in front of a jury, because a trace proves exposure, not impairment.
The lab often measures leftovers
Your body breaks a drug down into metabolites, and many of them are inactive. They cause no impairment at all; they are the ash after the fire. With marijuana, the main inactive metabolite can linger in blood or urine for days or weeks after any effect has worn off, up to 30 days in urine. A positive for the leftover points to past use, not impairment at the wheel. The guide walks through which results mean what, in plain English.
The expert is an officer with a checklist
When alcohol is not the issue, the State often calls in a Drug Recognition Expert. The title sounds medical. It is a job description. A DRE is a police officer running a fixed twelve step routine, and the routine reaches its opinion at step eleven, before the lab result is even known. The final step is the lab report, which is then said to confirm the opinion the officer already reached. The guide shows how that order builds in bias, and how the opinion can be challenged, limited in scope, or excluded.
Where to get it
The guide is free, and one email unlocks it along with the whole Safir Guides library at thesafirlawyer.com/free-guides. The full web coverage of prescription, marijuana, and other drug cases lives in the drugged driving section of my site.
If your matter is urgent, skip the reading and get in touch. Every case is different and no outcome is promised, but a positive test is where the questions start, not where they stop. You’re better Safir than sorry.
The book
Arrested for DUI in Florida
What a forensic lawyer-scientist wants you to know before you plead: the ten day license clock, the breath machine, the roadside exercises, and the three roads out of a DUI. Free to Tampa Bay residents facing a charge, with the digital edition to read the moment you ask.
About the author
Rory Safir is a St. Petersburg attorney who handles injury claims and criminal defense across the Tampa Bay area. He is one of a handful of ACS-CHAL Forensic Lawyer-Scientists in Florida and a former Assistant Public Defender in Tampa, and he brings that same evidence-driven approach to fighting for injured clients.
