Experienced Nashville Defense Firm

Question of Serum or Whole Blood Extremely Important in BAC Tests

A conviction for driving under the influence can result in license suspension, community service, heavy fines and jail time. However, the blood-alcohol tests used in Tennessee to convict those charged with DUI may not tell the whole story.

With that in mind, let's consider the case of a 26-year-old Tennessee man whose DUI trial is set for May. The young man was injured in an accident and hospitalized, and local police suspected that he was driving under the influence. A sample of his blood was sent off for toxicology testing, and the test results indicated that his blood-alcohol level was 0.21 percent.

However, in its report, the state lab did not specify something extremely important: whether whole blood or blood serum was used in the testing.

The distinction can have immense bearing on DUI cases because tests of blood serum indicate significantly higher blood-alcohol levels than whole blood tests. Serum contains higher water levels, which can have a higher content of ethyl alcohol. A conversion must be done on serum results to get a more accurate number.

Since the report did not indicate which type of test was used, the man's attorney contacted the Tennessee Bureau of Investigation and ultimately learned that the defendant's serum, rather than whole blood, was used, thus inflating the test results.

After the appropriate conversion was completed, it turned out that the man actually had a blood-alcohol content of 0.1779. This is still above the legal limit for driving, but the manner of testing nonetheless has major implications in Tennessee. Here a BAC of 0.20 percent or higher can result in a mandatory week in jail.

The defense in this particular case was able to have the charge against the defendant downgraded.

Anyone accused of DUI should avail themselves of professional legal assistance early in the case. A DUI defense attorney can help prevent overcharging and other negative consequences that could result from faulty police work or mistakes on the part of the prosecution.

Source: Times Free Press, "Attorneys challenge DUI test results from hospitalizing crash case in Chattanooga," Beth Burger, April 27, 2014