After a driver is arrested on suspicion of driving under the influence of drugs or alcohol, the police generally take a chemical test sample to check for drugs or alcohol in the driver's body. If drugs and/or alcohol are found in the driver's test sample, this may be used as evidence against the individual in a criminal trial.

However, these blood and breath tests are not always accurate and a mistaken test result should not be the basis for a conviction. Talk to your Virginia DUI defense lawyer about your DUI charges and how to challenge DUI blood test results.

When Do the Police Take Blood Samples in Virginia DUIs?

In most cases, law enforcement will require a breath or blood sample after a DUI arrest in Virginia. There are generally two reasons why the police will take a blood test sample instead of a breath test in a Virginia DUI case. They include

• Suspected impairment by drugs, or
• Driver incapable of giving a breath test.

Blood Tests in Drug DUIs

Breath tests only test for the presence of alcohol. These tests take a sample of the driver's air from their lungs and use that measurement to estimate the driver's blood alcohol content (BAC). However, breath tests do not test for drugs, controlled substances, or the presence of other materials which can impair a driver's ability to safely operate a vehicle.

If law enforcement suspects the driver is impaired by drug(s) or the combination of alcohol and drugs, they will generally take a blood sample instead of a breath sample. There are a number of reasons why the police may suspect the driver is under the influence of drugs (as opposed to just alcohol), including

• Odor of drugs,
• Possession of a controlled substance,
• Driver admits to taking drugs,
• Presence of drug paraphernalia, or
• Observations of the driver.

Driver Unable to Provide a Breath Sample

If a driver is arrested and is incapable of taking a breath test, the driver may be required to submit to a blood test. A driver may be incapable of giving a breath test if he or she cannot give a full breath required for the testing device, is unconscious, or is unable to follow instructions.

Can I Refuse a DUI Blood Test?

Under Virginia's implied consent law, drivers are considered to have given their consent to post-arrest chemical testing, including blood tests. Pursuant to Code of Virginia § 18.2-268.2, any person operating a vehicle in the Commonwealth of Virginia is deemed to have consented to have samples of blood and/or breath taken for a chemical test to determine the alcohol and/or drug content of his or her blood within three hours of the alleged offense.

It is not considered a crime to refuse a chemical test. However, there is a civil penalty for refusing a chemical test after a DUI arrest. Refusing a chemical test carries a mandatory one-year license suspension and the driver is not eligible for a restricted driver's license in Virginia.

Drugs Identified in a DUI Blood Test

A blood test in a DUI case is much more comprehensive than a breath test. Breath tests only check for alcohol in the body, generally based on the blood alcohol concentration (BAC). For most drivers in Virginia, a BAC of 0.08% or higher is a per se violation of the Commonwealth's drunk driving laws.

DUI blood tests look for alcohol as well as a number of other substances. These tests primarily look for drugs or chemical identifiers or certain narcotics, prescription drugs, or other substances that may impair a driver's ability to safely operate a vehicle. This may include:

• Marijuana/Cannabis,
• Opiates (Oxycodone, morphine, Vicodin, heroin, etc.),
• Amphetamines (MDMA, methamphetamines, etc.),
• Cocaine, and/or
• Benzodiazepines (Xanax, Valium, etc.)

Problems with Blood Testing in Virginia DUI Cases

Blood tests are supposed to be accurate measures of how much alcohol is in the individual's body and what types of controlled substances are found. However, these tests require following certain policies and procedures to make sure the tests are accurate.

There are a number of problems which can cause blood tests to give false or exaggerated test results. This may result in a driver testing positive when he or she has not taken any drugs, or even showing a negative result for a driver who is under the influence. Factors causing mistakes in blood test results can include:

• Improperly labeled samples,
• Mixed up samples,
• Unclean testing equipment,
• Contamination of samples or testing equipment,
• Failure to follow testing procedures,
• Not observing the test subject before the sample is taken,
• Equipment not calibrated, or
• Lab technicians falsifying results.

There are also innocent reasons why a driver may test positive for drugs that are unrelated to taking a controlled substance. This includes taking certain over-the-counter medications, medical conditions, or even eating certain foods, like poppy seeds.

Challenging Blood Test Results

An experienced Virginia DUI defense attorney understands how to challenge blood test results. This generally involves making a motion to suppress the use of chemical test results and keeping these tests from being introduced as evidence in court. If the motion is successful, the prosecutor may have no evidence of a driver's BAC or drug presence. Without any evidence, the prosecutor may be forced to drop the case.

A common basis to challenge blood test results involves showing the police or testing facility did not follow the proper regulations and procedures for blood testing. This includes showing the proper chain of command, sterilization, anti-contamination measures, identification and recording of the sample, and timeliness of the sample. If the proper procedures were not followed, the blood test may be inaccurate and should not be used as evidence against the defendant.

Charlottesville Drug and Alcohol DUI Defense Lawyer

Blood testing in Virginia DUI cases is not always accurate. Your DUI defense lawyer can investigate what happened in your case and identify all the ways to challenge inaccurate and unfair test results to fight against a criminal conviction so you can keep your license. Contact me today for a free consultation.