Rising BAC Defense

In Michigan it is against the law to have a blood-alcohol concentration (BAC) over .08 when you are driving. However, because alcohol must be absorbed into the blood stream via the stomach and small intestine, it may be under the legal limit when driving but over at the time you are being tested. For normal social-type drinking, the highest BAC is usually achieved within 30 minutes after completion of consumption, though it could take as long as 60 minutes. When large amounts of alcohol are consumed over a short time interval, or when a large quantity of food is eaten when drinking, the absorption phase may not be complete for up to two (2) hours after last consumption. In other words, as noted above, your BAC may actually rise over the legal limit after the stop.
Often times, after being stopped, it may take than an hour for you to be given a blood, breath or urine test. For instance, let’s say you are stopped and arrested and then transported to the police station where, about an hour after the initial stop, you are then given a Datamaster Test. On the Datamaster, you blow a .09. Chances are that when you were actually pulled over, your BAC might have been .07 and kept rising in the hour it took to get you to the station and wait the statutory 15 minute observation time. It may also be a good idea to refuse the initial PBT (a civil infraction that will cost you $100.00), but if you blow over the legal limit, any possibility of cutting a deal with the prosecutor may be futile.
The flip side of this defense, however, is that when a person is stopped and arrested for drunk driving, and is no longer consuming alcohol, as time passes his BAC will begin to fall. For that reason and to negate a Rising BAC defense, police officers will try to test you as soon as possible.
Furthermore, because of this defense, police officers generally ask how many drinks you consumed, and when. Don’t do their job for them and tell them. There is also a presumption under the law, that the blood alcohol level found when you are tested was the same level as when you were driving. In addition,when advancing this defense, the burden of proof is on the Defendant, which means you will have to get an expert toxicologist to testify at your trial and could be costly On the other hand, that still may be a better investment than getting hit with an Impaired or DUI conviction.