You get pulled over, you take some field sobriety tests and consent to a breath test. (NOTE: in Massachusetts you are not required to take a breathalyzer or any field sobriety tests.) You take the Breathalyzer and you blow a .10. You had a few drinks, and your last drink was right before you left the bar. At the time you get pulled over, your blood alcohol content (BAC) could actually be lower than it was when you were driving.
The funny (not in a laugh out loud sort of way, but in an ironic sort of way) is that it is totally legal to have a blood alcohol of .08% when you are standing in the police station blowing into a breathalyzer. Just because the machine says you have a .10 or .11 does not mean that an hour or so earlier, when you got pulled over, that you had a blood alcohol of .10 or .11, in fact it is possible that your BAC when you were driving was in fact below the legal ‘per se’ limit of .08.
Truth be told, if you are taking a breathalyzer at a police station, your blood alcohol when you were driving could actually have been higher then when you are standing at the station blowing into the tube. When you are drinking your body is absorbing and eliminating alcohol simultaneous, and therefore your blood alcohol is always changing.
If you tried to play it safe and wait a few hours after your last drink, and you consent to a blood alcohol test, your BAC when you were driving and got stopped was higher, and this argument won’t help. (There are other arguments and evidence that can be used to challenge the legitimacy of a breathalyzer so if you took one, it does not mean you will automatically be convicted).
If you had a couple of drinks with friends and finished your last one just as you were leaving and you got pulled over on the way home (and felt relatively fine), and you take a breath test, there is a possibility that your BAC was higher at the police station than it was when you were operating your car.
If you took a breathalyzer you should contact an experienced defense attorney like me, Jessica A. Foley, you can email me at firstname.lastname@example.org or call me at 866-981-7888.