Both questions will be answered in this section. However, breath testing is very complicated and the explanations given in this section will, of course, be simplified. For further explanation, feel free to call Arnold Terrill Anzini, P.C. to speak with an experienced criminal defense attorney.
When drunk driving enforcement first began, the Government had to prove you were guilty of driving a motor vehicle while intoxicated. Proving that someone is drunk can sometimes be difficult to prove if an officer is not properly trained or if the case is not sufficiently investigated by the Government. The breath test was developed originally to assist the officer in determining whether or not someone was intoxicated.
Because of a desire by most State Legislatures to make it easier to convict drunk drivers, most states enacted "Per Se" (pronounced Per Say) laws. "Per Se" laws made it against the law to be over a certain limit, whether you were proven to be intoxicated or not. Thus, the breath test became used by the Government to prove a certain Blood Alcohol Content (BAC).
The history of breath testing is rather long and not relevant to the breath testing today. However, it is interesting to note that the very first breath test instrument was developed in the State of Indiana and was called the Drunkometer. Older devices such as the Drunkometer were not as reliable or as scientific as some of todays instruments and, most importantly, were not as practical because they required a great deal of care and maintenance. Even today, scientists continue to work to create better methods for testing.
Most evidentiary breath testing is now done by use of infrared light. The State of Indiana mostly uses an instrument called the BAC DataMaster. The DataMaster is manufactured by National Patent Analytical Systems in Mansfield, Ohio. The DataMaster is used by about 15 to 20 stated in the U.S. and is also used in Canada and several other countries overseas.
Infrared breath testing relies on the premise that infrared light will be absorbed by the alcohol molecule. Inside the DataMaster, infrared light is directed through a chamber in the instrument. The light goes through the chamber and hits a detector at the end of the chamber. The detector expects to see a certain amount of light.
When a person blows breath into the instrument, the infrared light will be absorbed by the alcohol molecules that exist in the chamber. The detector notices that some light is missing and then makes a calculation, based on a computer program. The end result of the calculation is meant to be the amount of alcohol, by weight in grams, in the persons breath.
There are many problems with breath testing. For example, the instrument assumes that all people have the same body temperature. And because body temperature can make a difference in the test result, there is possible error there. Also, the instrument assumes that all people have the same amount of water in the body. Because water obviously dilutes alcohol, the amount of water can be a factor in each case.
It is believed by many that infrared testing is a good way to test for breath alcohol. However, there is a built in possibility for error as listed above. In addition, the instruments are not always used properly by the states. Any evidentiary testing of a quantity or amount of any substance requires a very accurate and thorough methodology. If the State does not use "good science" in employing the instrument, then the results are only as reliable as the procedure.
There are many scientific articles that outline the minimum standards to be followed by any State in order to properly use a breath test instrument. Please be sure to contact an attorney with specific training within this area of the law should you have additional questions. If you wish to discover more about breath testing, please contact Arnold Terrill Anzini, P.C. to speak with an attorney.