You’re pulled over on suspicion of drunk driving. You’re subjected to field sobriety exercises (FSE) and arrested for DUI. You’re then required to take a breathalyzer test, and you blow above a 0.08 – the legal limit for drunk driving in Florida.
That’s an open and shut case, right?
Despite what the prosecution wants you to believe, it’s not that simple. As an experienced DUI defense attorney and one of just four ACS-CHAL Forensic Lawyer-Scientists in the state of Florida, I understand the limitations of breath tests, and I use that knowledge to defend the rights of people accused of DUI.
There are several legal strategies an attorney can use to fight back against a breathalyzer test result. They broadly fall into two categories: challenging the breath test itself, and challenging the legal procedures surrounding the test.
Challenge the breath test machine
Breathalyzers, like any other measuring device, need to be properly calibrated. If the device wasn’t calibrated – more to the point, if the prosecution can’t prove the device was calibrated – then the test results may be thrown out entirely or at the very least discounted in importance by the jury.
Furthermore, even a properly calibrated machine may not always produce an accurate result. Technically, a breath machine doesn’t measure alcohol; it detects chemical compounds in the “methyl group,” which includes alcohol but also several other compounds that can be found on human breath under some circumstances. For instance, diabetics with low blood sugar may have high levels of acetone on their breath, which the breathalyzer “sees” as alcohol. Smokers may have elevated levels of acetaldehyde, which also “looks like” alcohol to the breath test. If you recently did some painting, siphoned gas, or engaged in other activities that involved industrial chemicals, then you may have certain compounds in your system that – you guessed it – a breath test would think are alcohol.
The point is that false positives happen. Inconsistent readings happen. An attorney who knows the science and the limitations of breath tests can undermine your BAC results on that basis.
Challenge the investigation and legal procedure
If the breath test was conducted as part of an illegal search, then the results are irrelevant; the prosecution can’t use them in court.
In order to pull you over, a police officer needs reasonable suspicion that you’re breaking a traffic law, for instance if you are visibly driving erratically. In order to administer the breath test, the investigating officer needs probable cause to believe you’re intoxicated, such as slurred speech or the smell of alcohol on your breath. A visible open bottle of alcohol in the vehicle could also qualify, but if the officer had to search your vehicle to find that evidence, the search also requires probable cause (or a warrant, or your consent – which is why you should never consent to a search).
There are numerous strategies an attorney can use to establish that the search was illegal. If successful, a Motion to Suppress can get the test results and any other evidence found during the illegal search thrown out, which may lead to your charges being dropped if there isn’t enough evidence left for the prosecution to move forward.
What if you refuse the breath test?
If you refuse a Breath Test, that is one piece of evidence the prosecutor does not have, but the jury may perceive it as suspicious. You need a DUI attorney who knows how to explain to a jury that people refuse to give a breath test for other reasons than the obvious "the driver refused because he knew he would have blown over 0.08.”
A DUI defense attorney can challenge the breath test and show you weren’t really intoxicated
Unfortunately, too many people end up convicted of DUI based on evidence that wouldn’t have held up in court if properly challenged. That’s why you need an attorney on your side who knows the rules, knows the system, and knows the science behind breathalyzer tests.
Remember, the clock started ticking as soon as you were pulled over. There are steps your lawyer needs to take promptly to protect your rights, and the sooner you get someone in your corner, the better. If you’re facing DUI charges in Polk or Hillsborough County, call or use the contact form to schedule your free consultation with an experienced attorney today.