In Georgia DUI cases, a blood test is often considered the “gold standard” of evidence by prosecutors. Unlike a breath test, which measures alcohol vapor, a blood test directly measures the concentration of alcohol or drugs in your bloodstream. However, blood testing is a complex scientific process that is vulnerable to human error, contamination, and procedural violations. At the Law Office of Gordon Hall, LLC, we know that a blood test result is not the final word in your case.
The Blood Draw Process: Where Errors Begin
The integrity of a blood test begins the moment the needle pierces your skin. Georgia law requires that blood be drawn by a qualified medical professional (such as a phlebotomist, registered nurse, or physician) in a medically acceptable manner. We investigate the draw itself for critical errors:
- Alcohol Swabs: If the person drawing your blood cleans your arm with an alcohol-based swab, the swab can contaminate the needle and the sample, artificially inflating your BAC reading. Protocol requires a non-alcoholic swab (like Betadine or iodine).
- Improper Mixing: Blood collection tubes contain two essential chemicals: an anticoagulant (to prevent clotting) and a preservative (to prevent fermentation). If the tube is not gently inverted to mix these chemicals immediately after the draw, the blood can ferment, actually creating its own alcohol inside the tube before it ever reaches the lab.
- Expired Tubes: If the vacuum tube used to collect the blood is expired, the vacuum seal may fail, or the preservative may degrade, rendering the sample unreliable.
Chain of Custody and Lab Analysis
Once the blood is drawn, it must be transported to the Georgia Bureau of Investigation (GBI) Crime Lab for analysis. This transportation process is called the “chain of custody.” If the state cannot prove exactly who had possession of the blood sample at every moment from the hospital to the lab, the evidence can be suppressed.
At the lab, the blood is tested using a machine called a Gas Chromatograph. This highly sensitive equipment requires precise calibration. We demand the lab’s testing data, calibration records, and chromatograms to ensure the machine was operating correctly and the forensic toxicologist followed proper scientific procedures.
Implied Consent and Warrants
You cannot be forced to give blood without your consent or a valid search warrant. If an officer coerced you into submitting to a blood test, or if they obtained a search warrant without sufficient probable cause, the blood test results can be thrown out as a violation of your Fourth Amendment rights.
Yes, you can refuse a blood test requested under Georgia’s Implied Consent law. However, doing so will result in an automatic administrative suspension of your driver’s license for up to one year. Additionally, the officer may then apply for a search warrant to force a blood draw.
Using an alcohol swab violates standard medical protocol for forensic blood draws. The alcohol from the swab can contaminate the sample, leading to a falsely high BAC reading. If we can prove an alcohol swab was used, we will file a motion to suppress the blood test results.
Yes. The GBI Crime Lab can test your blood for the presence of both legal and illegal drugs. However, simply having a drug in your system is not enough for a DUI conviction; the state must prove that the drug made you “less safe” to drive.
It can take anywhere from a few weeks to several months for the GBI Crime Lab to process a blood sample and return the results. Your attorney will monitor this timeline and use any unreasonable delays to your advantage.