Challenging the Breath Test

Maintenance and inspection rules

The Intoxilyzer 8000 is not a fire-and-forget device. Under FDLE rules, each instrument has to pass agency inspections, be kept in working order, and have its checks documented. Those records are discoverable, and they are not always clean. When an inspection is missed, when an instrument is used past a required check, or when the paperwork that lays the foundation for admitting a breath result is incomplete, the State's case for putting that number in front of the jury weakens. Reading these records the way the rules require is the first thing Graham Syfert does with a breath case.

The observation period

Before a valid sample, the officer is supposed to observe the subject for a set period, commonly twenty minutes, with no belching, regurgitation, smoking, or anything placed in the mouth. The point is to make sure the machine measures deep lung air and not alcohol lingering in the mouth. On a busy DUI night, that observation is sometimes done while the officer is also writing reports, talking on the radio, or processing paperwork. A short or distracted observation period is a concrete, factual basis to question whether the rules were followed and whether the reading means what the State says.

Mouth alcohol

Mouth alcohol is alcohol that never reached the lungs — from a recent drink, a burp, acid reflux, dental work that traps fluid, or even some breath sprays. Because the machine assumes the breath it samples came from the lungs, mouth alcohol can drive a reading far above the true blood-alcohol level. A proper observation period is supposed to prevent it; when that period was rushed, mouth alcohol becomes a real and testable explanation for an inflated number.

The rising blood-alcohol curve

Alcohol takes time to absorb. A person can be below the limit while driving and above it an hour later at the station, because the alcohol from a last drink is still entering the bloodstream. The law cares about impairment at the time of driving, not at the time of the test. When there is a meaningful gap between the stop and the breath sample, the rising-curve problem can mean the reading overstates what mattered, and that gap is something the defense can put squarely in front of the jury.

Operator error and the human factor

The machine depends on the person running it. The operator has to be properly permitted, follow the testing sequence, and document each step. Skipped steps, an interrupted test, an instrument used outside its parameters — each is a place where the result can be challenged, sometimes excluded, and sometimes simply undermined enough that a jury stops trusting it. Whether any of that wins depends on the facts of the case, which is why the records and the video get examined closely from the start.

Related: back to challenging scientific evidence; see also drug field test errors and DNA evidence challenges. If you have been arrested, start with Jacksonville DUI defense.