Testing Blood Alcohol

Your BAC or Blood Alcohol Content, is what most people think about when they think about DUI. Law enforcement and the State Attorney's Office rely heavily on BAC as well. In Florida, if at the time you were driving, you had a BAC of .08 or above you are DUI. (See section on DUI misconceptions for a full discussion of this) For people under the legal drinking age of 21, they can be cited at a .02 for a civil infraction and license suspension, even though they are not DUI.

Types of Testing:

Breath Test
Blood Test
Urine Test

Breath Tests

The State uses an 8000 series Intoxilyzer machine to measure a person's BAC. It basically uses an infrared light absorption method to analyze the deep lung air of a suspect. Two breath tests are required and a 20 minute observation period must occur prior to the test.

The machine is subject to errors. Many of them are as follows:

Radio Frequency Interference (RFI)
Inadequate Machine Maintenance
Male vs. Female Test Subject
Lung Capacity
Ethnicity
Breathing Pattern
Partition Ratio
Breath Temperature
Problematic/Defective Machine
Outdated Software
Individual Machine Variance
Inadequate Maintenance Records
Source Code Errors

Taking the test and blowing at or over the .08 level generally results in a 6 month driver's license suspension. A hardship permit is allowed after the first 30 days. Refusing the test results in a 12 month suspension with a 90 day period before a hardship license is allowed. A second refusal, (if the person had a prior refusal) is a criminal offense in the State of Florida.

Blood Tests

A second method for measuring a BAC is a blood test and there are two categories of blood tests: Legal and Medical. A legal blood draw is done when taking someone to the breath test facility is impractical. (usually when an accident is involved). An officer asks someone qualified to draw blood (a nurse or paramedic usually) to take the sample and it is sent off to FDLE (Florida Department of Law Enforcement) for testing.

A medical blood is where the State obtains the blood results by subpoena from a hospital when the hospital takes a blood sample during the course of their normal functions. The State must notify the accuse at least 10 days prior to the issuance of the subpoena of their intent to do so.

Consent must be given to draw blood with two exceptions: One, when an accident resulted in death or serious bodily injury. In this case, law enforcement can forcibly take a blood sample.

The second exception is when the suspect is unable to give consent (unconscious, but no serious bodily injury to anyone and no death). Consent is "assumed" since the right to drive in Florida has an "implied consent agreement when you get a license. (look at the fine print at the bottom of your license).

Urine Tests

Urine tests are used to determine if someone is under the influence of a controlled substance. It is a poor method, standing alone, since drugs can remain in a persons system long after their affect has worn off. Different drugs remain in a system for differing periods of time and a persons physiology can affect the time as well.

As Chief of the State's DUI unit, I pressed for a blood test to be given rather then urine, since, if a drug is still in a person's blood stream, they are still under the affect of the drug. This method was not adopted.