Today is training day at the Center of American and International Law hosted by the Texas Criminal Defense Lawyers Association. The program is focused on the defense of DWI in Texas, particularly the defense of breath test cases. The thought-provoking approach to defending the DWI breath test case boils down to one of 4 related strategies.
Going Head-to-Head with the State's technical supervisor by attacking the accuracy of the breath test result. In other words, was the breath test result accurate beyond being simply valid. Just because a breath test result is regurgitated from the machine and is a valid result, that doesn't mean it reveals an accurate determination of my client's breath alcohol level at the time of driving.
Garbage-In/Garbage-Out. There are many variables of human physiology which the breath test machine makes assumptions about. It makes the assumption my client's breath was a certain temperature. It makes assumptions about the ratio of alcohol in my client's breath compared to the alcohol in their blood. It assumes the breath sample came from the deep lung area rather than my client's mouth. There are many more problem assumptions which show if garbage goes in, then garbage comes out.
Believe What You See. The best DWI breath test defense often hinges on a good video. If my client looks reasonable good (sober) on the police video, how could the breath test result over the limit possibly be right? It is a great common sense defense that jurors can easily relate.
No Extrapolation. Regardless of my client's breath test result at the police station - the jury must still believe beyond a reasonable doubt the test result would have been over the legal limit at the time of driving. This is because the human body absorbs and eliminates alcohol from the body over time. It is possible the breath test result at the time of driving was less (under the limit) than at the time of the test.
Anyway, I always enjoy training and hearing about the experiences of other successful criminal defense lawyers. My clients will benefit from the hard work of others. Fellow defense lawyers Hunter Biederman and Robert Guest are attending. Check out their blogs for comments on the conference.