Breathalyzer Accuracy

Breathalyzer accuracy has long been debated by Fort Lauderdale DUI defense lawyers, prosecutors, judges, law enforcement and manufacturers of the machines.

It matters because breathalyzer results are central to most Florida DUI convictions. These machines are not infallible. They sensitive to environmental conditions and must be properly maintained and used by their human handlers – who of course make sometimes make mistakes.

Any good defense of a Florida DUI case involves analysis of the breathalyzer. We want to know:

  • Technical methodology of that particular make and model (mostly Intoxylizer 8000 in Florida);
  • Manufacturer’s recommended proper use and maintenance;
  • How that particular device was maintained/ calibrated;
  • What environmental conditions existed at the time of the test;
  • Whether person taking the test had any medical conditions that could have produced a false result;
  • The extent of officer’s training to use the device.

And of course, we’ll be looking at whether the officer had reasonable suspicion to stop you in the first place and probable cause to believe you were intoxicated in order to direct you to take the test in the first place.

How Breathalyzers Work

By Florida law – F.S. 316.193 – it is unlawful to drive under the influence of alcohol such that your normal faculties are impaired. One way police can establish this is by showing your breath-alcohol concentration met or exceeded 0.08 grams of alcohol per 210 liters of breath. This finding is what is known as a per se offense, meaning it’s automatically illegal to drive with that breath-alcohol concentration – regardless of whether police can prove your normal faculties were impaired.

The term “breathalyzer” is a mash-up of the terms “breath” and “analyzer,” and is a brand name trademarked in the 1950s, but widely used today to refer to any generic device that tests one’s breath-alcohol concentration.

The devices are either desktop or handheld, and technology utilized is either infrared spectrophotometer or electrochemical fuel cell. The first involves using infrared light to measure molecules, while the other measures certain electrochemical reactions.

Some of the factors that might influence these tests include:

  • Individual body temperature.
  • Failure to differentiate between ethyl alcohol and other compounds of a simple chemical nature.
  • Electrical interferences.
  • Consumption of certain foods or other substances.
  • Medical conditions or medications.

There is also sometimes discrepancy between the alcohol in one’s breath and the alcohol in one’s blood, which is the truer measure of one’s intoxication. Often, one’s blood-alcohol concentration lags behind their breath-alcohol concentration. This is called rising BAC, and it could be a viable defense if your BAC was at or just above the legal limit.

Defense lawyers in one high-profile case did at one point seek to subpoena computer source code records from the Kentucky-based maker of the Intoxylyzer 8000, with the ultimate goal of suppressing that evidence. Defense argued such records would provide information on the accuracy of the machines’ readings. However, the Florida Supreme Court in Ulloa v. CMI ruled that in order to subpoena documents located in another state in possession of an out-of-state nonparty, the requesting party must follow the procedure set forth in Chapter 942. Defense attorneys may be able to get around this by seeking out-of-state employees of the company to testify in Florida criminal proceedings.

Breathalyzer Calibration

One of the most frequent challenges to breathalyzer test results has to do with calibration.

Rule 11D-8.007 of the Florida Administrative Code stipulates that Intoxilyzer 8000 devices must:

  • Only be accessible to a person issued a valid permit by the department;
  • Be located in a secure environment limiting access by unauthorized persons;
  • Be kept clean and dry.

The state has a number of other additional rules about how often the device must be calibrated/ maintained. If these provisions aren’t followed, it could be grounds to challenge the test.

Implied Consent/ Refusal to Blow

Although police need to have a warrant (in most cases) to conduct a non-consensual blood draw of a DUI suspect, the same is not true of breathalyzers. Of course, they can’t conduct a breathalyzer test without at least some cooperation from the person being tested, as that individual must blow into the device.

Florida’s implied consent law, F.S. 316.1932, stipulates that drivers who refuse to undergo a breathalyzer test at the direction of an officer will receive an automatic one-year license suspension.

However, as our Fort Lauderdale DUI defense lawyers can explain, there could be some situations where it’s better not to blow at all, rather than knowingly submit to a test you’re pretty sure you will fail.

Breathalyzer test results can be a powerful piece of evidence against you, and you may want to avoid giving prosecutors any more ammunition. They will be able to use your refusal to submit against you in court, but they will still have to provide other circumstantial evidence to prove their case.

Consulting with an experienced defense lawyer after any arrest is important to minimizing the impact and mounting a successful challenge.

If you have been arrested for DUI in Fort Lauderdale, call The Ansara Law Firm today for your free initial consultation at (954) 761-4011.