Driver stopped at Sobriety Checkpoint Roadblock. He admits to screening officer that he had a couple of drinks at concert and is returning home with his girlfriend. Police note the standard clues of impairment to include slurred speech, glassy/bloodshot eyes and an odor of alcohol. Driver does reasonable well on fields sobriety tests but is .10 BrAC on both Portable Breath Test (PBT) and post arrest breath test. PBT evidence is not admissible in Massachusetts. Defense challenge to scientific reliability of Draeger Device excludes post arrest breath test evidence .10. Defense focuses on good driving performance through checkpoint and screening areas and field sobriety testing as recorded by police. Not Guilty Verdict following trial.