Kevin Drum is concerned by a California Supreme Court that makes it easier for defendants in DUI cases to challenge the validity of the breathalyzer test. They ruled this way because the test varies based on a wide variety of factors.
Drinking and driving is a serious problem and a lot of steps to fight including checkpoints and ignoring possible error in the testing during prosecution can certainly help to reduce this problem. That is not good enough because saving lives is not the only concern of government. Government must also be concerned with protecting civil liberties.
If the law states that you cannot drive with BAC above .08 and you are pulled over and measure in at .09 but there is reason to believe that the device was flawed and you were actually .07, this is relevant. Sure, you probably shouldn’t be driving at .07, but it isn’t against the law, and our legal system is intended to assure that no innocent person is ever convicted, even if the cost is letting guilty people go free occasionally.
So if we are to honor our legal principles (which I think we should), it is only right that we allow challenges to the accuracy of the tool used as evidence of guilt, even if that ability leaves it open to abuse. Going even further, we should probably do away with DUI checkpoints altogether, as they amount to fishing expeditions, “searching” individuals without ever displaying a reasonable suspicion of the commission of a crime.
As a side note, once at a bar I played the breathalyzer “game” (you pay a buck and blow into the hole and it tells you your BAC). I blew a .1 when it probably should have registered something somewhat below that (say a .07. The thing is, I did not wait the instructed time between my previous drink and doing the test, overestimating my BAC. When I am just messing around at a bar (prior to walking back to my hotel), that error is meaningless, but if a similar error were involved in a driving situation, suddenly an innocent (according to the law) individual is being found guilty.
