Let’s say that you are on trial for DUI and the prosecution claims you had a high blood alcohol concentration, even though you really had a low blood alcohol concentration. How is the prosecution going to prove their case? The answer is relation back argument.

What Is A Relation Back Argument?

When a person consumes alcohol, they don’t immediately have a blood alcohol concentration. The alcohol has to go first through their digestive system, their blood, and eventually, into the brain before it affects their ability to think and act.

In the same way, when you eliminate the alcohol from your body, either through sweat, breath or urine, it takes some time to develop a blood alcohol concentration. This means that you start with a higher blood alcohol concentration, and as you begin to eliminate it, you slowly move to a lower blood alcohol concentration.

The argument the prosecution is making is that when you breathed into the breath machine or when you gave blood, the alcohol in your blood had already reached a lower level. But, when you were driving, the alcohol in your blood was at a higher level.

However, there are a lot of problems with this argument. In fact, it is one of the most specious that can be made in a DUI case.

One of the most important scientists on the side of the government was Swedish chemist A.W. Jones, who created the relation back argument. However, he stated that it could not be used to establish a prior breath alcohol or blood alcohol concentration because there are simply too many variables in the human body.

What Does The Prosecution Need To Prove?

The most important variable isn’t the human body but that the prosecution can almost certainly not establish that you were in the elimination phase. This is because there is the absorption phase when your body is absorbing alcohol, and then there is the elimination phase; when your body is getting rid of alcohol. In fact, you probably were not in the elimination phase because it takes some time to get there.

Once you stop drinking, your BAC continues to go up. Most people have a drink, get in the car, and go. If the police officer stopped you within the first hour after your last drink, then you were almost certainly in the absorption phase going up, not in the elimination phase, going down. This would completely throw off the calculations that they use for this relation back argument.

How Can An Attorney Fight The Relation Back Argument?

Your attorney needs to understand the relation back argument and be prepared for it in court. If you have any questions about the relation back argument or any other area of the law, please feel free to call me.