Police pull out to follow driver with defective headlight. He slows in presence of marked cruiser but otherwise drives normally. Driver states he pulled off highway to rest following long drive home from Patriots game. He admits to drinking at the game, but not for quite some time. Driver does reasonable well on field sobriety tests and discloses his history of knee problems. Defense Motion to Exclude Breath Test for failure to establish valid 15 minute observation period is granted. At trial defense submits medical records to establish history of knee injury. Not Guilty finding following trial.