For years prosecutors and defense attorneys in Florida have been battling over the use of breath testing instruments. Defense attorneys have vigorously sought release of the intoxilzyer “source code”. Most judicial circuits in Florida have held that the “source code” is a trade secret and exempt from release. What the source code contains is scientific terms on how these devices gathers and interprets evidence gathered during a breath sample.
Recently, the 3rd District court of Appeals affirmed a lower courts ruling that the intoxilyzer results cannot be used as “presumptive evidence” of an intoxication until the device’s reliability is revealed and explained. According to this article in Keys News, prosecutors must call expert witnesses to explain how the machine works.