Let’s cut right to the chase. You want to contest the results of a blood alcohol test?

Get a lawyer. One who specializes in DUI defence. The methods used to contest blood alcohol tests – and impaired driving charges in general – are incredibly complex. You’re not going to be able to do it on your own, and you’re definitely not going to be able to do it by reading a blog.

That said, let’s take a look at some of the avenues an attorney might use to contest a blood alcohol test.

Mandatory breathalyzer tests

For years, police had to have a reasonable suspicion that a driver was under the influence before they could mandate them to take a breathalyzer test. What amounted to reasonable suspicion was variable. An officer might pull someone over if they saw them leave a bar and start driving, if their driving was erratic, or for any other number of reasons.

In Manitoba, this is no longer the case: officers can administer mandatory breathalyzer tests without reasonable suspicion. That complicates one of the more common defences against DUIs.

That said, there are arguments that mandatory breathalyzer tests without reasonable suspicion are unconstitutional. We won’t get into those here, as they’re very complex, and unlikely to be used as a defence – but it’s something that’s worth mentioning in the context of this post.

The bolus defence

Also known as the intervening drinking defence, this defence is sometimes viable when you blow under 0.08 on a breathalyzer test, but at or over 0.08 on the subsequent blood alcohol test. 

Here’s the gist of the defence, sometimes known as the “last drink defence” – it takes some time for your body to process alcohol. If you had a drink, then immediately hit the road, it’s possible your body wouldn’t have metabolized that drink until you got home. In other words, your blood alcohol would never have reached .08 while you were driving.

For pretty obvious reasons, a lot of people really hate this defence – they say it encourages binge drinking before leaving a bar. No matter what your stance is on the defence, however, it is sometimes viable in the courtroom.

Refusing a breathalyzer test

In Canada, you can be criminally charged for refusing a breathalyzer test. That means that if an officer requires you to take a breathalyzer test, it’s generally a good idea to accept the test, even if you think you may end up testing over the limit. Accepting the test means you may have recourse to legal defences you wouldn’t otherwise, like the bolus defence.

These are just a few of the many things to keep in mind when contesting a blood alcohol test. Again, the most important thing to do is ensure that you have a solid legal defence – and a great Winnipeg criminal lawyer will provide you with just that. DUI charges are among the most complicated legal scenarios you can encounter, and everything from your actions to the actions of the arresting officer can have important consequences to your defence.