Saturday, September 04, 2004
Extrapolating Blood Alcohol Content Measurements
In many cases, a person arrested for drunk driving does not have his or her blood alcohol content (BAC) checked (at least by a certified tester) until well after the traffic stop. In the meantime, the body goes on metabolizing alcohol -- that is, the person sobers up a bit. What happens if a breathalyzer test is administered, say, two hours after the arrest, and the person records a BAC of .05? Is that enough evidence to convict him of DWI, given a per se standard of .08? Does .05 now imply .08 or above two hours ago?
It appears as if an appeals court ruling in North Carolina means that, in the Tar Heel state, the answer to that question is "yes" -- for legal purposes, alcohol decays at the rate of .0165 per hour. Here's the story, from the Winston-Salem Journal.