DUI Per Se – BAC Greater Than .08

If you’re charged with a DUI, you may have been charged with a DUI “per se.”  This law  has nothing to do with impairment caused by drugs or alcohol.  Instead, the per se law makes it a crime to drive with a blood alcohol content of more than .08 – regardless of how the alcohol affected your ability to drive.  This law applies in most states and can be used to help bolster the prosecutor’s claim that you were drunk (thereby helping to prove a second charge that you were indeed impaired).

The Origin of the Per Se Statutues

A group of reformers in the 80s known as Mothers Against Drunk Driving (MADD) mounted a national campaign to reign in what sometimes were permissive state laws regarding DUI. They managed to get some scientists to opine that anybody with a BAC of .10 or more could reasonably be considered to be under the influence, so why not create a shortcut and cut out the need to show bad driving or lack of capacity. Ultimately the figure was reduced to .08 by the National Highway Traffic Safety Administration (NHTSA). And federal transportation money for states was conditioned on adopting .08 as a separate offense. The fact is, .08 is highly arbitrary given the various tolerances that many people have developed over a lifetime of drinking and the variability in rates of absorption and metabolism. However, the folks in charge were not inclined to give this "tolerance" defense to the criminal defense lawyers, so .08 it is.

Challenging a Per Se Charge

There are a few ways to challenge evidence that shows a BAC of .08 or higher.  However, over the years the legislatures have closed most of the loopholes that were developed by defense attorneys when these laws first came in, and many people end up pleading guilty to this offense even though their ability to drive was not, in fact, affected.

As a general rule, most people charged with DUI plead guilty if a breath or blood test shows a BAC of .11 or higher, but are more inclined to fight if the amount is .10 or less. In fact in some states you get a boost if your blood alcohol content was less than a particular amount (typically .05) under laws that presume you to not to be under the influence.

As a reminder, we're just talking about alcohol here. Currently there are no laws that prohibit you from driving with a certain level of a particular drug in your system, but as marijuana continues to gain traction as a legal drug under some circumstances, such laws are sure to come.

Minors and the Per Se Statutes

If you are under 21 (or 18 in some states) about half the states prohibit you from having any alcohol in your blood and you can be charged with DUI for even a trivial amount. In the other states, minors are limited to a .02 blood alcohol content. Zero (or low) tolerance laws prevail with the hope of preventing our young people from dying on the highways because of drunk driving.

Get Help From an Attorney

If you’ve been charged with a DUI and you want to fight the charge in court, seek help from an experienced attorney who is familiar with the laws and procedures in the county where you were charged. 

Excerpted and adapted from Beat Your Ticket: Go to Court & Win, by David W. Brown (Nolo).