BAC retrograde calculation in DUI conviction is ‘inherently unreliable’

BAC retrograde calculation in DUI conviction is ‘inherently unreliable’

Many Wisconsin residents enjoy having a few drinks with dinner or when going out for the evening. While some people may feel extremely intoxicated after having a few drinks, others may be somewhat more tolerant to alcohol. Each person is unique in their ability to process and eliminate alcohol from the body. Factors, including age, body mass index and the amount of food the person has consumed, also play a large role in determining the amount of time it takes for the alcohol to move through a person’s system. Anyone who chooses to drive after drinking, however, may face DUI charges in Wisconsin.

An Illinois woman argued that the individual variances in a person’s ability to handle alcohol created reasonable doubt as to whether she was legally intoxicated while driving. This happened after an incident at a local aquatic center in 2011. At that time, the woman was arrested and charged with a DUI. Although the Breathalyzer test indicated that her blood alcohol concentration level was 0.069 percent an hour after the incident occurred, the prosecution attempted to prove that her BAC was over the state’s legal limit of 0.08 percent at the time of her arrest. A jury found her guilty of the charge in 2012.

An expert used a retrograde extrapolation calculation to estimate the woman’s BAC at the time of the incident. The judge later found the evidence to be unreliable due to the inherent differences in a person’s ability to retain and eliminate alcohol. Her conviction has since been overturned.

Being convicted of a DUI in Wisconsin can wreak havoc on a person’s life. A criminal defense attorney may be extremely helpful in providing essential legal counsel to those who face DUI charges.

Source: Daily Herald, “Court overturns Carpentersville woman’s 4th DUI,” Harry Hitzeman, July 16, 2014.