Challenging breath test results
Prosecutors in Florida and around the country usually rely on breath test results to prove intoxication in drunk driving cases, but this kind of evidence can sometimes be challenged. The devices police officers use to measure the amount of alcohol in a DUI suspect’s blood are extremely sophisticated, but they only provide accurate results when they are properly maintained and calibrated.
Magic black box
Civil rights advocates and legal experts have been questioning the validity of breath test results for many years. Judges in Massachusetts and New Jersey excluded more than 30,000 breath tests in 2019 after determining that the equipment used to conduct them was unreliable, and a panel of judges in Florida described the testing device used by law enforcement agencies in the Sunshine State as a “magic black box.” To determine whether or not the devices used to measure their blood alcohol concentrations were reliable, drunk driving suspects should ask prosecutors to provide calibration and maintenance records.
The Fourth Amendment
Breath test results may be excluded in a DUI case even if the equipment used was working perfectly if the police officers involved initiated a traffic stop that violated rights protected by the Fourth Amendment. Police officers are only permitted to pull vehicles over when they have good reason to do so, and they can only ask drivers to submit to breath tests when they notice signs of intoxication like slurred speech or the smell of alcohol.
People who are charged with driving under the influence of alcohol often believe that mounting a defense is futile because the evidence against them is scientific and cannot be challenged, but this is not always the case. Thousands of drunk driving cases are dismissed each year because police officers acted improperly or the devices they used to measure blood alcohol levels were faulty.