Controversial DUI Two-Beer Defense to be Reviewed by Canadian Supreme Court


The Supreme Court of Canada has recently agreed to evaluate the controversial "two-beer defense" against breathalyzer tests, and the upcoming judicial decision should be an interesting development in how Canadian defendants are allowed to disprove DUI charges in the future.

Canadian critics have protested this argument, in which defendants claim they drank "only two beers" or something to that effect in a spread-out period of time, and thus could not have been drunk driving.

In fact, these critics have become worried that a substantial number of Canada DUI charges have not led to convictions because of the use of the "two-beer defense."

Essentially, the "two-beer defense" relies on the fundamental flaws with breathalyzer testing procedures, which are not 100% certain.

In order to estimate a person's blood alcohol content, breathalyzers must make certain assumptions. For example, when converting breath alcohol content into BAC, breathalyzers assume a specific ratio of 2100:1 between the two.

However, this ratio may vary between 1700:1 and 2400:1 for individuals. In other words, a person may argue that he or she is not "average" and that breathalyzer findings do not apply since they may have been influenced by his or her weight, metabolism rate, eating habits during that day, and other factors.

Canadians Robert Gibson and Martin Mac-Donald have used the "two-beer defense" to appeal their Canada DUI convictions based on their breathalyzer test results.

ccording to a story in The Saskatoon StarPhoenix, Gibson was arrested on suspicion of DUI in 2003 after registering a BAC that was 1.5 times the legal limit of 0.08. Prior to his conviction, Gibson argued that he had consumed 10 beers in seven hours, and that due to his weight, his BAC would have fallen to a level that was below the legal limit.

Mac-Donald registered a 0.14 BAC reading during his February 2003 arrest but later argued during his trial that he drank six beers, spaced evenly, in 3½ hours that night. An expert later testified that Mac-Donald may have fallen below the legal limit.

While both men lost their original cases, the fact that they have been able to appeal to the Supreme Court based on the "two-beer defense" has concerned many people in Canada. In fact, the Conservative federal government recently introduced legislation to eliminate the defense.

How the Canadian Supreme Court rules on the "two-beer defense" will provide a good indicator of whether DUI defendants have to prove they were actually under the legal BAC limit or merely show that the possibility they were below 0.08% existed.

While the "two-beer defense" is not a common procedure in the United States, American defendants often fight breathalyzer results based on the fact they are not the "average person" and that breathalyzer conversion methods do not apply to them.

In other instances, a defendant may win a DUI case by successfully challenging the initial grounds for the arrest, or disputing the arresting officer's questioning or testimony.

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