Chemical Testing - Inherent Errors
Whether submitting to a blood, breath or urine test, the ultimate goal is to determine BAC levels in the body. According to the law in most states, any chemical test administered two to four hours after the alleged driving is presumed to be the BAC level at the time of driving. This presumption allows the defendant to present evidence that refutes the test result, such as recalculating the BAC level by factoring absorption and metabolic rates and numerous other factors that distort chemical test results.
Since alcohol continues to absorb into the bloodstream for approximately 50 minutes after the cessation of drinking, many chemical test results indicate a higher BAC level than at the time of driving. Most defendants are stopped within 15 minutes of their last consumption of alcohol, and are administered chemical tests approximately 45 minutes after the initial police stop. Naturally, the test result will be higher and the defendant could be wrongfully charges with drunk driving. This, it is possible to argue that the chemical test result is inaccurate because it inflates the actual BAC level at the time of driving.