Impairment is not usually shown by blood drug levels – Fairfax DUI lawyer

Impairment cannot ordinarily be established by blood drug levels, says Fairfax DUI lawyer

Impairment cannot usually be established by blood drug levels. As a DUI attorney in Fairfax, Virginia, I know that the totality of the circumstances must be considered in determining whether a DWI defendant has been proven guilty beyond a reasonable doubt, rather than resorting to the overly facile approach of looking at blood alcohol and blood drug levels.

Impairment should not be dictated by per se DUI laws, but those laws too often command that

Since around 2000, it has been a crime throughout the United States to drive with a blood alcohol level of 0.08 or higher. Additionally, throughout the nation driving under the influence of drugs also is a crime. Unfortunately, Virginia DWI law automatically sets the following criminal threshold for driving with the following drugs in one’s bloodstream: “(a) 0.02 milligrams of cocaine per liter of blood, (b) 0.1 milligrams of methamphetamine per liter of blood, (c) 0.01 milligrams of phencyclidine [PCP/ angel dust] per liter of blood, or (d) 0.1 milligrams of 3,4-methylenedioxymethamphetamine per liter of blood.” Va. Code § 18.2-266. That list thankfully leaves out such popular substances as marijuana, opiates, LSD and other psychedelics.

Marijuana remains in the bloodstream too long for marijuana blood levels by themselves to prove impairment

Marijuana’s key cannabinoid THC typically remains in one’s bloodstream for a week or several weeks, making marijuana blood level insufficient by itself to prove impairment. While other drugs typically remain in the bloodstream for a shorter time than marijuana, the presence of a certain level of drugs in one’s body ordinarily by itself does not establish impairment.

Additionally, the Virginia Department of Forensic Science toxicologist who examines the blood of a DUI-drug defendant might sometimes agree on the witness stand on the limited causation between blood drug levels and driving impairment, and might also confirm that the level of prescription-type or over-the-counter medicine in the particular defendant’s bloodstream (at least if taken as directed) is of a therapeutic and not impairing level.

The benefits of a Virginia DUI defendant’s hiring a defense expert

Rather than hoping that the DFS toxicologist (who is a Virginia state employee) will provide any testimony beneficial for the criminal defendant, it is best for a Virginia DUI defendant to consider the option of hiring a private forensic toxicologist to testify about the weaknesses of post-arrest testing for alcohol or drugs in the defendant’s blood or breath. I have repeatedly used the services of such private toxicologists, often with beneficial court results.

Because of the serious penalties for a conviction for driving under the influence of alcohol or drugs, it is important to not get behind the wheel within twenty four hours of consuming alcohol, not to drive at all for a long time after consuming illegal drugs, and to consult with one’s physician about any possible driving impairment from driving after taking medication.

Virginia DUI lawyer Jonathan L. Katz pursues your best defense against DWI, misdemeanor, felony, drug, and marijuana prosecutions, To discuss your case with Jon Katz, please call his staff at 703-383-1100 to schedule a confidential consultation.