In the State of Florida it is not illegal to operate a motor vehicle with a Blood Alcohol Level above .01 unless you are driving a commercial motor vehicle. To obtain a conviction for DUI the State must prove beyond a reasonable doubt that the Defendant is under the influence of alcohol, a chemical substance or a controlled substance, to the extent that their normal faculties are impaired. Florida Statutes have set .08 Blood Alcohol Level (BAC) as the legal limit. Under Florida’s DUI law if a person is operating a motor vehicle and their BAC is .08 or higher they will be presumed under the influence of alcohol.

An accurate blood alcohol level is crucial because it can be the difference between a DUI conviction and a not guilty verdict at trial. An experienced DUI attorney should understand the different ways that blood alcohol level can be tested and the weakness of each.

A person may not have a 0.08 or more grams of alcohol per 100 milliliters of blood which seems like a simple of enough rule; however, blood can be tested with different methods. One method is to test the subject’s "whole blood" where the actual, unaltered sample is removed from the subject and tested. It could be argued that this will give you the most accurate BAC reading because no conversion is necessary to come up with the BAC.

The second method of testing blood alcohol content is conducted on the blood serum (blood absent the red blood cells) or blood plasma. Case law has held that testing partial blood (i.e. blood serum) for proving blood alcohol content may be relevant. The trial and appellate courts held that a test that determined blood alcohol level by blood serum was inadmissible because testing blood absent the red blood cells could result in a false reading. However, in 1996 the Florida Supreme Court ruled expert testimony converting blood content from a percentage of blood serum to a percentage of whole blood was not inconsistent and should be allowed. This was an important decision because most hospitals test blood serum, which is where most blood testing is done.

Florida Statute 316.1934 creates a presumption of impairment for the jury if the BAC is .08 or greater. For the State to use this presumption in a blood serum case they must show that the medical blood was extracted by a person listed in Florida Statute 316.1934 (2)(c) and tested by a medical lab technician licensed to conduct and interpret serum tests. If the State can’t show compliance with the statutory requirements they can’t use the presumption of intoxication based on the .08 or greater BAC reading. However they can still admit the BAC reading into evidence and obtain a conviction based on it measuring a .08 or greater. Bottom line is if you have a BAC reading based on the results of the blood serum it is admissible as evidence of intoxication but an experienced DUI attorney can successfully attack the accuracy of the BAC reading even though it is admissible in evidence.