Challenging DUI Chemical Test Results in Court
Many people believe if they fail a breath or blood test, they’re automatically guilty of DUI. This belief is not entirely misplaced. The conviction rate in blood test cases is over 90 percent. The conviction rate in breath test cases is not much lower (around 80 percent in most jurisdictions). Although these numbers are daunting, they still give a lawyer an opportunity to successfully resolve DUI test cases.
This successful resolution could be a plea to a lesser-included offense, a complete dismissal of charges, or a not-guilty verdict at trial. For a Leesburg criminal defense lawyer, a successful resolution is a process, not a result. This process is especially complex in DUI test cases, since these matters involve both scientific and legal issues. As is always the case in criminal law, this process also involves a thorough case evaluation, diligent evidence collection, and assertive advocacy in court and around the negotiating table.
Challenging DUI Blood Test Results
This process typically focuses on accuracy, procedure, and constitutional issues. Although blood tests are considered reliable, they are not automatically conclusive. There’s a difference between the two.
- Legally Compliant: In Virginia, a qualified medical professional must draw the blood. Not all phlebotomist techs, especially at large medical facilities, qualify under this law. Additionally, police officers must have valid search warrants before a technician draws blood. The warrant must be issued by a neutral magistrate, in writing, and based on probable cause (usually field sobriety test results).
- Chain of Custody: The prosecution must prove the sample was properly labeled, stored, transported, and tested without contamination or mix-ups. Any unexplained gap can undermine reliability. Unreliable blood samples are of almost no value to prosecutors in court.
- Testing Procedures and Lab Protocols: This issue is closely related to the qualifications of a medical professional. Possible procedural issues include improper storage temperature, fermentation of the sample, expired chemicals, machine calibration errors, or failure to follow forensic standards.
A Leesburg criminal defense lawyer may order independent retesting of the sample. Frequently, the results an independent professional obtains are different from the results a police-affiliated technician claims s/he obtained.
Challenging Breath Test Results in Court
Despite all its bells and whistles, today’s Breathalyzer is an updated version of a 1920s Drunk-O-Meter. The flaws inherent in that 100-year-old device remain in Breathalyzers. These flaws, which are especially significant in borderline BAC cases, include:
- Mouth Alcohol: If the subject burps or belches prior to the test, the alcohol particles that rush into the mouth from the stomach skew Breathalyzer results. Police officers hardly ever observe a mandatory pre-test monitoring period designed to eliminate this flaw.
- Device Calibration: As a matter of law, the Breathalyzer result is unreliable unless the device in question was properly maintained, Breathalyzers in general were properly maintained, and the department pulled nonfunctioning devices from service. Device calibration is one of the most frequent Breathalyzer flaw issues.
- Temperature Changes: All the aforementioned bells and whistles make the Breathalyzer especially vulnerable to external and internal temperature changes. The outside temperature often changes suddenly and unexpectedly in Virginia. Furthermore, a slight body temperature elevation could skew the result.
Once again, a Leesburg criminal defense lawyer typically partners with an independent expert, like a degreed chemist, to drive home these flaws with jurors.
Work With a Diligent Loudoun County Lawyer
There’s a big difference between an arrest and a conviction in criminal law. For a confidential consultation with an experienced criminal defense attorney in Leesburg, contact Simms Showers, LLP, Attorneys at Law. Convenient payment plans are available.
Source:
tdcaa.com/journal/new-to-dwi-prosecution/
