Answer:
The rising blood alcohol defense argues that alcohol continued entering the bloodstream after driving, so a later test may show a higher BAC than the driver had while operating the vehicle.
Alcohol is not absorbed instantly. If a driver consumed a drink shortly before leaving a bar or restaurant, the person’s blood alcohol concentration may continue to rise after the vehicle was stopped.
Colorado prosecutors must prove impairment or the applicable alcohol level at the time of driving. A chemical test taken much later may reflect a higher concentration than existed when the person was behind the wheel.
The timing of drinks, driving, the stop, and testing is therefore important. A Denver DUI lawyer can analyze that timeline and determine whether a rising blood alcohol defense fits the evidence.