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Commonwealth v. Matthew Sibley 2009 PA Super 84 (5/05/2009)

Topic: DUI – Blood Alcohol Content (BAC) – Coefficient of Variation

Summary: Where the coefficient of variation fails to indicate that the defendant may have been operating a vehicle while below the legal limit, the evidence is sufficient to support the conviction.

Illustration: Sibley was charged with DUI with a blood alcohol level above 0.16%. There was a 3% coefficient of variation. Sibley argued that with this variation, his blood alcohol level may have been anywhere between 0.157% to 0.167% and the evidence was therefore insufficient to support his conviction. The Superior Court concluded that, since the evidence showed that Sibley’s BAC was between 0.157% to 0.167%, the evidence was sufficient to support a conviction of DUI with a 0.16% blood alcohol level (The question of what the precise BAC was goes to the weight of the evidence).