What Does It Mean To Be “Impaired” For A DWI?

Posted on by lmrlawoffice

If you are charged with driving while impaired (a DWI) then the police officer claims you were “impaired” while driving your car.  (For what it means to actually “drive” a car for a DWI see the blog post on this site titled “What Does It Mean To “Drive” A Vehicle For A DWI?”).

So what does “impairment” mean exactly?  Does it mean you were stone cold drunk?  Do you even have to be “drunk” to be impaired?  Is alcohol the only substance that can make you “impaired”?  What if the police officer never asked me to blow into his machine on the side of the road?  What if I didn’t blow into the police officer’s machine on the side of the road or at the jail?  How can the police claim I was drunk if I never blew into any machine?

Under NC law, in order to be convicted of a DWI the police and prosecutor must prove in court that you were “impaired” at the time you were driving your car.  According to N.C.G.S. 20-138.1 (NC’s DWI law), there are three ways you can be “impaired.”

The three ways you can be “impaired” for purposes of a DWI are:

  1. If you were “under the influence” of an impairing substance, or

  2. You had a blood alcohol concentration of 0.08 or more at any relevant time after driving, or

  3. You had any amount of heroin or any other Schedule I controlled substance in your system. 

If the prosecutor can prove that any one of the above three situations applies to you then you were “impaired.”

What does it mean to be “under the influence”?

“Under the influence” has been taken by the courts to mean you’d drunk enough to lose the normal control of your mental or physical faculties to such an extent that you were “appreciably impaired.”

What does it mean to have a blood alcohol concentration of 0.08 or more?  

That means the State can show that when you blew into the machine at the jail your blood alcohol level was at least a 0.08.

What does it mean to have had any amount of heroin or any other Schedule I controlled substance in your system?  

That means if there is any trace of heroin or some other drug listed in Schedule I of the North Carolina Controlled Substances Act you can be “impaired” for purposes of a DWI.  It won’t matter how much or how little of the heroin or Schedule I controlled substance actually is in your blood at the time of the DWI, all that matters is that there is some level of it in your system.

It’s not like with alcohol where the State must still show you were appreciably impaired to convict you of a DWI.  If your blood was drawn by the police it was probably sent to the State Crime Lab for analysis to determine whether you had any heroin or other Schedule I controlled substance in your blood.

If the lab says you did have heroin or another Schedule I controlled substance in your blood (no matter how little) the prosecutor can show you were “impaired.”

Does it mean you were stone cold drunk?  Do you even have to be “drunk” to be impaired?

Even if you didn’t feel drunk, if the prosecutor can show you were either “appreciably impaired” or blew at least a 0.08 or had a Schedule I controlled substance in your system then that will be enough.

Is alcohol the only substance that can make you “impaired”?  

No.  While alcohol is the most common way to be impaired, it is certainly not the only way.   Marijuana can make you impaired for purposes of a DWI.  There’s no magic minimum amount of marijuana the prosecutor must show was in your system at the time of the DWI and there’s no requirement that the prosecutor show you consumed marijuana a certain time before the DWI.  If the prosecutor can show you had enough marijuana in your system to make you “appreciably impaired,” then that might be enough.

Prescription drugs like Ambien and Oxycodone can make you impaired as well for purposes of a DWI.  Having a prescription to take these kinds of medicines is not a defense to a DWI.  In other words, having a prescription for your drugs doesn’t mean you can’t be guilty of a DWI.

What if the police officer never asked me to blow into his machine on the side of the road?

Police officers don’t have to ask you to blow at the roadside.  They may have felt that they had enough evidence of your impairment already.  If you did blow into their tube on the side of the road the police (and blew at least a 0.08) the police can use that against you when deciding whether to arrest you for DWI.  The judge at your DWI trial won’t ever know the actual number you blew on the roadside but can be told by the prosecutor whether your blow was positive or negative for alcohol in your system.

What if I didn’t blow into the police officer’s machine on the side of the road or at the jail?

If you were asked by the police to blow into their machine at the roadside or at the jail but you declined their offer (which is legal, by the way), that fact can be used against you at your DWI trial as evidence of possible impairment.

How can the police claim I was drunk if I never blew into any machine?

“Blowing into the machine” isn’t the only way for the police to show you were impaired.  Remember, your blood alcohol level (which blowing into the machine determines) is only one way to show you were impaired.  If the police and prosecutor can show you were “appreciably impaired” by your bad driving, poor performance on the roadside sobriety tests, admission to drinking, etc., then it won’t matter that you never blew into any machine.

If you’ve been charged with DWI and have questions similar to these the best thing you can do is hire a former DWI prosecutor.  As a former DWI prosecutor I know the answers to your questions and the inside legal knowledge to help you win your case.  I’m available 24 hours a day/365 days a year to take your call.  My number is (919) 886-7506.