The Massachusetts Appeals Court addressed the issue of proving a motorist has a blood alcohol content over .08 under the per se law when there is a substantial time lapse between the time of the breath test and driving observations. This issues frequently arises as one of the many defenses in an OUI charge with breath test results.
The Appeals Court in Commonwealth v. Dacosta recently upheld a defendant’s conviction on the “per se” charge of operating a vehicle with a BAC level of .08 or greater when the defendant’s BAC level was tested approximately an hour after the traffic stop. According to the Court, no “retrograde extrapolation” evidence was required where a breathalyzer test was administered 55 minutes after the traffic stop. To learn about the science behind retrograde extrapolation see the attached Article by Kurt Dubowski.
The defendant was stopped when an officer noticed a faulty inspection sticker on the windshield. During the stop, the officer observed that the defendant had red glassy eyes and so administered two sobriety field tests. The defendant failed both tests, and so was arrested and transported to a nearby police station.