DUI

The Role of Blood Tests in DUI Cases

Driving under the influence (DUI) is a serious offense that can lead to severe legal consequences. In most DUI cases, determining the driver’s level of impairment is a crucial element in deciding guilt or innocence. While breathalyzer tests are commonly used at the scene of a suspected DUI, blood tests often play an even more critical role in gathering evidence. Blood tests are typically more accurate than breath tests and can detect not only alcohol but also drugs that might impair a person’s ability to drive. Understanding how blood tests are used in DUI cases and their legal implications is essential for anyone facing these charges. The science behind blood tests, their accuracy, and how they are conducted can have a significant impact on the outcome of a DUI case. The Bateman Law Firm provides experienced legal guidance and aggressive defense for individuals facing DUI charges, ensuring their rights are protected and striving for the best possible outcome in each case.

350+ Reviews
5.0 Star Average

avvo clients choice-DUI

How Blood Tests are Conducted in DUI Cases

When a driver is suspected of driving under the influence and fails a breathalyzer test or refuses to take one, law enforcement may request a blood test. This procedure is typically conducted at a hospital or medical facility. In most cases, a police officer will transport the suspect to the location where the blood draw will take place. A licensed healthcare professional draws the blood, ensuring that the procedure follows strict legal and medical protocols to maintain the integrity of the evidence. Once the blood sample is collected, it is sent to a laboratory for analysis. The purpose of a blood test in a DUI case is to measure the concentration of alcohol or drugs in the driver’s bloodstream. Blood alcohol concentration (BAC) levels are measured in grams of alcohol per 100 milliliters of blood. In South Carolina, the legal limit for BAC is 0.08% for drivers over the age of 21. For those under 21, the legal limit is much lower at 0.02%. The BAC level can provide strong evidence of impairment, and blood tests are often seen as more reliable than breathalyzer tests because they offer a direct measurement of the substances present in the blood.

Accuracy and Reliability of Blood Tests

Blood tests are generally regarded as one of the most accurate methods of determining alcohol or drug levels in the body. This accuracy is largely due to the fact that blood tests provide a direct measurement of the substance in the bloodstream. However, while blood tests are reliable, they are not infallible. Errors can occur at various stages of the testing process, from the collection of the sample to its storage and transportation. If a blood sample is not handled correctly, it can become contaminated or degraded, leading to inaccurate results. Additionally, the timing of the blood test is crucial. Alcohol levels in the bloodstream fluctuate over time. If the test is conducted hours after the driver was initially stopped, the BAC may no longer accurately reflect the level of impairment at the time of driving. This is particularly important in DUI cases, as it may raise questions about whether the driver was actually impaired while operating the vehicle. The reliability of the blood test results can become a key point of contention in court, and an experienced attorney can challenge the evidence if there are grounds to believe that the test was not conducted properly.

Legal Implications of Blood Test Results

The results of a blood test can have a significant impact on the legal outcome of a DUI case. A positive blood test indicating a BAC above the legal limit can lead to charges such as driving under the influence or driving with an unlawful alcohol concentration. However, the presence of drugs in the bloodstream, even those prescribed by a doctor, can also lead to DUI charges if they impair the driver’s ability to operate a vehicle safely.

"He has an innate ability to convey to clients what really matters in their cases."

"John Bateman is my absolute go to peer in the legal field when it comes to questions about DUI. . . . He has an innate ability to convey to clients what really matters in their cases. As a fellow attorney, I highly recommend John to anyone in the SC or NC areas who are looking for... legal representation when facing a DUI charge."

M. Brock

"An excellent DUI attorney. He has received the same field sobriety test training as all police officers in the State"

"John is an excellent DUI attorney. He has received the same field sobriety test training as all police officers in the State, and also the same training as the people who are the instructors of the police officer training courses on field sobriety tests. He is very passionate about DUI's and I recommend him often to people who are facing serious charges in the upstate area."

P. Hammond

"He cares for each of his clients and works extremely hard to achieve results."

"Very knowledgeable and thorough in his preparation and representation of his clients. He cares for each of his clients and works extremely hard to achieve results. I highly recommend this lawyer."

C. Grubbs

 The legal consequences of a DUI conviction can be severe, including fines, license suspension, mandatory alcohol education programs, and even jail time. For repeat offenders, the penalties are even more stringent. Because blood test results can play such a pivotal role in securing a conviction, it is essential to scrutinize the test’s accuracy, handling, and interpretation. One of the challenges that arises in DUI cases involving blood tests is that the results alone do not prove impairment at the time of driving. For instance, certain drugs may remain detectable in the bloodstream long after their impairing effects have worn off. A driver may test positive for a drug like marijuana or prescription medication, even though they were no longer impaired by the substance at the time of the traffic stop. In these situations, an attorney can argue that the presence of drugs in the bloodstream does not necessarily equate to impairment.

Challenging Blood Test Evidence in Court

There are several grounds on which blood test evidence can be challenged in court. One of the most common challenges is related to the chain of custody of the blood sample. From the moment the sample is collected until it is presented in court, there must be clear documentation showing that the sample was properly handled and stored. If there are any gaps in this chain of custody, the validity of the test results can be questioned. Another potential challenge involves the qualifications of the person who conducted the blood test. Only licensed professionals are legally permitted to draw blood for DUI cases. If the test was conducted by an unqualified individual, the results could be deemed inadmissible in court. Similarly, if the blood test equipment was not properly calibrated or maintained, this could call the accuracy of the results into question. Finally, the timing of the test may be contested. If there was a significant delay between the time of the traffic stop and the blood test, the results may not accurately reflect the driver’s condition at the time they were operating the vehicle. These and other factors can be used to challenge blood test evidence and potentially reduce or dismiss the charges.

Related Videos

Refusing Field Sobriety Tests

Choosing a DUI Attorney

Refusing a Blood Test and the Consequences

In South Carolina, implied consent laws state that by driving on the state’s roads, a person automatically consents to chemical testing, including breath, blood, or urine tests, if they are suspected of DUI. Refusing to take a blood test can have immediate consequences, including the suspension of driving privileges. A refusal can also be used as evidence against the driver in court, as prosecutors may argue that the refusal indicates guilt. However, drivers do have the right to refuse a blood test, and there may be valid reasons for doing so. For instance, some individuals may be concerned about the accuracy of the testing process or may have concerns about their medical privacy. While refusing a blood test may complicate a DUI case, it does not guarantee a conviction. An experienced attorney can help navigate the legal complexities of a refusal and work to minimize its impact on the case.

The Role of an Attorney in Blood Test DUI Cases

Facing a DUI charge that involves blood test evidence can be daunting. The complexities of the testing process, the potential for errors, and the legal ramifications of the results make it critical to have strong legal representation. An attorney plays a crucial role in challenging blood test evidence and protecting the rights of the accused. An experienced attorney will investigate every aspect of the blood test, from the initial traffic stop to the collection, handling, and analysis of the blood sample. They will examine whether law enforcement followed proper procedures, whether the blood test was administered legally, and whether there were any issues with the chain of custody. By thoroughly scrutinizing the blood test evidence, an attorney can identify potential weaknesses in the prosecution’s case and use them to the defendant’s advantage. In cases where the blood test results are accurate and lawful, an attorney can still work to negotiate a more favorable outcome, such as reduced charges or lighter penalties. In many cases, the goal is to minimize the long-term impact of a DUI conviction on the individual’s life, including preserving their driving privileges and protecting their criminal record. Blood tests play a critical role in DUI cases by providing reliable evidence of a driver’s impairment through the measurement of substances in the bloodstream. However, the accuracy and reliability of these tests can be called into question based on how they are administered, handled, and interpreted. With the serious legal consequences that can arise from DUI convictions, it is essential to have an attorney who can skillfully navigate the complexities of blood test evidence. If you are facing a DUI charge in South Carolina and your case involves a blood test, it is crucial to seek the legal guidance of a knowledgeable attorney. The Bateman Law Firm is committed to protecting your rights and ensuring that you receive the strongest possible defense. Contact The Bateman Law Firm today to discuss your case and learn how we can assist you in fighting your DUI charges.