Everyone who walks into a Florida breath testing room is carrying a transmitter. The operator has a portable radio. The arresting officer has a phone, a body camera on his chest, and more often than not a smartwatch. The instrument they are about to use was built to notice that, and in a recent case it did.
The first breath sequence aborted on an “RFI Detect” exception. The samples the State ended up relying on read 0.179 and 0.182, more than twice the legal limit. The suspension was still set aside. Here is why, because the reason is more interesting than “the machine glitched.”
What actually happened, minute by minute
Observation of the driver began at 18:12. The first breath sequence ran, and at 18:35 the instrument aborted on RFI Detect. Radio frequency interference is precisely what that alert exists to catch, and the cause was not a mystery: an officer from a different agency had walked into the testing room with active equipment on him. He stayed for several minutes, walking the operator through his own agency’s procedure on mouthpieces.
The operator’s attention went where you would expect. He worked out where the interference was coming from, directed the other officer out of the room, satisfied himself the electronics were clear, and re-entered the test data. The operative samples came at 18:42 and 18:45.
The paperwork looked fine
This is the part worth understanding. On the face of the breath affidavit, observation started at 18:12 and the sample came at 18:42. That is thirty minutes. It clears twenty with room to spare, and if you are skimming, the form looks clean.
But rule 11D-8.007(3) of the Florida Administrative Code does not ask for a span of time somewhere in the file. It requires the operator to reasonably ensure that the subject has taken nothing by mouth and has not regurgitated for the twenty minutes immediately preceding the test actually administered. For an 18:42 sample, those twenty minutes run from 18:22 to 18:42. That is the exact window in which an unauthorized person entered the room, the instrument aborted, and the operator turned to troubleshooting.
A completed observation is not a credit you earn once and spend later. Its sufficiency depends on whether the assurance ran unbroken up to the test that produced the number.
The operator said so himself
Asked directly whether a full observation preceded the operative samples, the deputy conceded that it did not. In his words, it just wasn’t a full twenty minutes observation due to the RFI.
That concession does more work than any expert could. It is not a defense lawyer speculating that something may have gone wrong. It is the State’s own machine flagging a problem, and the State’s own operator confirming what the flag cost.
Why the concession was fatal, and not just a ding on the weight
The usual answer to observation challenges is that the standard is forgiving. An operator does not have to maintain fixed, unblinking, face-to-face observation, and doubts about the quality of his attention go to the weight a factfinder gives the result, not to whether it comes in at all.
That rule is real, and it did not apply here, because it presupposes the one thing this record lacked: a completed twenty minute observation. The doubt-goes-to-weight principle governs cases where the operator was present the whole period and only the sharpness of his attention is in question. Where the operator concedes the period was never completed, there is nothing to weigh. The predicate the rule demands is simply absent. Insubstantial deviations do not invalidate a test, but the proponent still has to show the test was conducted substantially in accordance with the rules. State v. Donaldson, 579 So. 2d 728 (Fla. 1991).
Who has to prove what
This is where administrative review cases are won and lost. Once a driver puts compliance in issue, the burden is on the Department to prove substantial compliance by competent substantial evidence. It is a departure from the essential requirements of law to flip that around and make the driver prove a violation. Dep’t of Highway Safety & Motor Vehicles v. Farley, 633 So. 2d 69 (Fla. 5th DCA 1994). The order of suspension does not arrive at the hearing carrying a presumption that everything was done right. And where the record holds an unexplained conflict about whether the observation happened, the hearing officer cannot simply credit the half that supports the suspension. Toth v. Dep’t of Highway Safety & Motor Vehicles, 27 Fla. L. Weekly Supp. 496a (Fla. 4th Cir. Ct. 2019).
The carry-forward argument, and why it fails
The State’s natural move is to say the rule expressly provides that no additional observation is required before a subsequent sample. That language exists, but it addresses the two or three samples that make up a single approved breath test. It does not carry an observation across an aborted test to validate the new one that follows. The test actually administered has to satisfy the observation requirement on its own. State v. Johnson, 30 Fla. L. Weekly Supp. 359a (Fla. Pinellas Cty. Ct. 2022).
Nor does the length of the interruption save it. In State v. Barcus, 31 Fla. L. Weekly Supp. 413b (Fla. Pinellas Cty. Ct. 2023), an officer stepped away for roughly a minute and a half and the results were held inadmissible, because he was no longer positioned to maintain close and continuous observation. Here an unauthorized person entered the secured room, the instrument aborted, and the operator spent minutes on troubleshooting. And an operator whose attention is necessarily directed elsewhere cannot simultaneously be doing the watching the rule requires. State v. Alain, 27 Fla. L. Weekly Supp. 388a (Fla. Volusia Cty. Ct. 2019).
The result
The hearing officer found the breath test was not conducted in substantial compliance with rule 11D-8.007, set the suspension aside, and the driving privilege was restored. The scope of a breath-test formal review is narrow, set by section 322.2615(7)(a): probable cause, and whether the driver had an unlawful breath alcohol level. Probable cause was never contested. Once the breath test could not be shown valid, the only basis for the suspension was gone.
What this means if you are the one who blew
Nobody had to prove the 0.179 was wrong. That was never the question. The question was whether the State could prove it followed its own rules, and on this record it could not.
Your breath printout, the agency’s records, and the operator’s own testimony carry far more than a number. They carry the attempts, the alerts, the aborts, and the times, and the times are where the rule bites. Plenty of Florida breath tests are run correctly, and whether any of this helps depends entirely on the facts of your case. But the file is worth reading closely by someone who knows what the timestamps have to line up with, and the window is short: you have ten days from the arrest to demand a formal review.
If you are facing a Florida DUI, the book that explains all of this in plain English is free. If you are a lawyer working a case where the breath instrument is the case, The Florida DUI Trial Manual covers the instrument’s own records, the chapter 11D-8 requirements, and how to cross the operator and the analyst. Either way, you are welcome to get in touch.
Every case and study behind this analysis is indexed publicly in the Florida DUI Reference, with most linked straight to the opinion on CourtListener or the paper on PubMed.
This post describes one past result and is general information, not legal advice. Every case is different, and past results do not predict or guarantee the outcome of any other matter. Identifying details have been omitted.
