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Normally in Florida, a blood test is conducted when a person is unable to provide a breath sample, usually as a result of injury from an accident.

While blood testing is generally accepted as one of the most accurate tests for DUI, it does have its faults. There are more ways for a DUI blood test to produce false results than there are for a DUI breath machine because there a many more steps in the process. These results can be challenged. Some of the best defenses to a DUI blood test include:

•Were the blood samples taken in a lawful way?  

•Was the blood drawn properly?

•Is there a clear chain of custody for the sample?

•Were the samples handles properly to ensure that they were not contaminated?

•Were the machines properly calibrated and maintained?

•Were proper scientific procedures followed?

•Did the technician operate the machine properly and follow all Standard Operating Procedures of the lab?

These are some of the questions that the state will have to answer. Every blood test has to be proven in court. There are no automatic convictions.

Numerous cases throughout the country have shown the fallibility of the DUI blood test machines.  Mr. Bernstein will aggressively challenge all of the evidence and actions of the police and prosecutor.


Mr. Bernstein has studied is highly trained in the scientific aspects of blood testing. He has attended intensive scientific training courses by The National College for DUI Defense specifically dealing with DUI Blood cases. He has also taught courses on Defending a Blood DUI. He has also been trained at Axion Labs on the instruments used to test someone's blood. 

Blood is sometimes taken after a DUI arrest to determine a person’s blood alcohol level when they are suspected of driving under the influence. It is likely the officer will request a blood sample if an accident occurred, especially if the driver or another person is taken to the hospital for injuries. If an officer suspects a driver may face felony DUI charges because of past convictions, a blood test also may be used.

If you submit to a breath or urine test, you also have the right to request an independent blood test. If the officer refuses to accommodate that request, your breath or urine test might be excluded from evidence.

Strict rules apply for this invasive form of testing. The blood can only be taken by a nurse, doctor, paramedic or other qualified medical professionals. The blood can only be taken if you go to the hospital or an ambulance for medical treatment. The blood test can detect the presence of alcohol or any chemical or controlled substance. Drivers who use drugs, including prescription medication, still can be charged with DUI for being under the influence of drugs. This form of DUI is often called "drugged driving" in Florida.

The officer can only legally obtain a legal blood test if you either consent or if exigent circumstances provide an exception to the warrant requirement. These issues are usually highly contested in court. In many cases, if the officer did not obtain a warrant, your blood test will be suppressed as being taken in violation of the Fourth Amendment. 


Florida's Method of Blood Test Analysis

Florida's crime labs typically run certain “immunoassay” tests as a preliminary screening process. The tests can determine the presence of certain types of drugs but not the quantity, which is important for concluding the driver would have been under the influence of the drugs at the time of driving. If such drugs are determined to be present, the crime lab may order additional testing on the sample.

This process of blood test cases is time-consuming for prosecutors in Florida. Florida's speedy trial rules require a misdemeanor DUI case be brought to trial within 90 days of the arrest. Although the prosecutor may be entitled to a 15-day recapture period, the 105-day period may not give the prosecutor sufficient time to prepare for trial.

When the blood sample is examined to find the presence of drugs during the preliminary "immunoassay" testing, a different type of testing is used called gas chromatography mass spectrophotometry or "GC-MS" for short. This form of analysis produces a graph of data points containing certain "peaks." The chemist with the crime lab or toxicology lab at the medical examiners can compare this data with known standards to determine the presence of certain illegal or prescription drugs.

In certain cases, state attorneys will attempt to use the blood test results from the hospital for the purpose of establishing the blood alcohol concentration. The hospital blood test typically is done on blood serum and not whole blood. 


Defenses to DUI Blood Test

Many Florida DUI suspects believe that a Florida DUI blood test is more accurate than a BAC result based on a DUI breath test.  Nothing can be further from the truth.  In fact, there are more ways for a DUI blood test to produce false results than there are for a DUI breath machine because there are so many more steps in the process of collecting, storing, analyzing, and reporting such results.

Some of the best defenses to a DUI blood test include:

  • Profiling of the forensic laboratory set-up and operation.  Science requires exactitude.  If the lab fails to properly set-up and operate within the requirements of science then the results of their conclusions are unscientific.

  • Improper venipuncture – Before, during and after blood is drawn from your body the phlebotomist must meet medically and legally accepted protocol.  Things such as, site preparation and blood extraction, needle gauge, type of needle used, vacuum tube used for collection and storage, and much more must be examined to ensure compliance with all health and legal codes.

  • Legal aspects of the DUI blood test were compromised – there are specific requirements for what a blood draw kit must contain.  The kit used in your case must be evaluated to ensure that all of the required components were present and used properly, the officer and technician followed the kit steps exactly as they are prescribed, the phlebotomist followed the hospital’s quality assurance procedures, the proper tubes were used for collection and storage, as well as the proper packaging, transport, and storage protocols were used.

  • Chain of evidence – evidence in a criminal case must meet certain legal requirements in order to be admitted in court against you.  One essential element of this is the requirement that police adequately explain the handling of evidence once they collected such evidence.  This requires asking the who, what, where and when questions.  Who touched it, what did they do with it, where did they take it, and when did they have possession?

  • Lab procedures – testing blood for BAC is done through the use of a Gas Chromatograph.  This machine must be examined to ensure it is reliable, properly cleaned, and properly maintained. If the machine cannot be verified, the results the machine produce cannot be verified.  Numerous cases throughout the country have shown the fallibility of the DUI blood test machines.

  • Cross-contamination – the machines used to test for the BAC level of DUI suspects are highly susceptible to cross contamination issues.  These machines are used to test thousands of different blood samples.  If the machine is not properly calibrated and cleaned it is highly likely that the results from the first test of the day will interfere with the test results of every subsequent test that day.

  • Education and training of the technician who tested your blood – many of the technicians who test the blood of a DUI Florida suspect have minimal training on the proper procedures for doing so. Just recently in many counties throughout the country it has been proven that lab technicians simply falsified various test results requested by law enforcement resulting in countless false convictions.

Generally, the blood test results are more accurate than the breath test results in determining if a driver was under the influence of drugs or alcohol. Although, in some ways, fighting the results of the test case can be easier than fighting the breath test case for several reasons:

  • Prosecutors typically are less experienced in prosecuting driving under the influence cases with a blood test result.

  • Blood test samples are handled by several people on their way to being tested and eventually being used in court. The state has to follow a strict chain of custody to have the results admitted in court. The state attorney often has a difficult time "tracking" the blood sample or proving the "chain of custody." If one part of that "chain of custody" cannot be established, the trial court may exclude any mention of the blood test at trial.

  •  At each point, it can be argued that the integrity of the sample has been compromised. If it has been compromised, it may not be admissible in court against you.

  • The state attorney often is required to present expert testimony before the results of the blood test are admissible at trial.

If you were arrested and have been charged based on a DUI blood test you need to understand that blood tests are not infallible.

Alan S. Bernstein P.A. - with offices in Broward and Palm Beach - handling cases in the counties of Broward, Dade, Palm Beach, Hendry and Glades, understands the science behind DUI blood testing, and how to defend you against this evidence.  Call right now for a free, no obligation consultation.  You only have 10 days to fight the suspension of your driver’s license.  Call right now! Call Alan S. Bernstein P.A. at 954-925-3111 or 954-347-1000 during the evenings and weekends.  

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